+ 2 physics test number - 1 one mark test year : 2015 ... · + 2 physics test number - 1 one mark...

+ 2 Physics Test Number - 1 One mark Test Year : 2015- 2016

Unit : 1 Electrostatics Total marks : 50 1. The branch of physics which deals with charges at rest is called as …………

a) current electricity b) electromagnetic induction c) electrostatic induction d) electrostatics

2. If an glass rod is rubbed with silk, it becomes …………

a) positively charged b) negatively charged c) positively and negatively charged d) uncharged

3. Bodies which do not allow the charges to pass through them are called …………..

a) conductors b) insulators c ) conductors and insulators d) none of the above

4. The force between two point charges q1 and q2 is given by the equation …………….

a) F = q1 q2 / 4πε o r3 b) F = q1 q2 / 4πε o r

2 c) F = q1 q2 / 4πε o r d) F = q1 q2 / 4πε o r

4

5. If charged bodies of charges 5q , -3q , -2q and 5q are brought in contact, then. the total charge = ……………

a) 15 q b) – 15 q c) 5 q d) – 5 q

6. The value of the permittivity of free space is ……………….. C 2 N

-1 m

-2

a) 8.854 X 10 -12

b) 8.854 X 10 12

c) 6.623 X 10 - 34

d) 1.6 X 10 – 19

7. For air, ε r = ……………….

a) 0 b) 1 c) 2 d) 3

8. The force exerted by an electric field E on a charge q is ……………..

a) F = E / q b) F = Eq c) F = q /E d) F = 1 / Eq

9. The unit of electric dipole moment is ……………..

a) C / m b) C 2 N

-1 m

-2 c) Js

-1 d) C m

10. The electric field at any point on the axial line of an electric dipole is given by the equation …………………..

a) E = p / 4πε o r 3

b) E = 2pcos θ / 4πε o r 3

c) E = 2pcos θ / 4πε o r 2

d) E = 2p / 4πε o r 3

11. The electric field at any point on the equatorial line of an electric dipole is given by ……………………

a) E = p / 4πε o r 3

b) E = 2pcos θ / 4πε o r 3

c) E = 2pcos θ / 4πε o r 2

d) E = 2p / 4πε o r 3

12. The torque experienced by an electric dipole in an electric field is given by …………….

a) τ = pE cos θ b) τ = pE sin θ c) τ = pE sin θ cos θ d ) τ = pE tan θ

13. The direction of the electric dipole moment is from …………. to ………….

a) + q , – q b) – q , + q c) ∞, – q d) ∞, + q

14. The net force on an electric dipole in an electric field is F = ………….

a) Eq b) – Eq c) zero d) infinite

15. The relation between the electric field and the electric potential is given by ……………

a) E = - dV / dr b) E = dV / dr c) E = -dr / dV d) E = dr / dV

16. The total number of electric lines of forces passing through the given area is called electric ………….

a) potential b) field c) flux d) potential energy

17. The unit of electric potential is ……………...

a) A m b) A c) volt d) Cm

18. The unit of electric intensity is ……………..

a) A b) V m -1

c) A m d) Cm

19. The equation of electric potential due to a point charge is ………………..

a) V = q / 4πε o r b) V = q / 4πε o r2

c) V = q / 4πε o r3

d) V = p cos θ / 4πε o r 2

20. The equation of electric potential at any point due to an electric dipole is ……………….

a) V = p cos θ / 4πε o r 2

b) V = p cos θ / 4πε o r 3

c) V = p cos θ / 4πε o r 4

d) V = q / 4πε o r

21. The work done to assemble the charges is called electric ……………….

a) potential b) field c) flux d) potential energy

22. The unit of electric flux is ……………….

a) C / m b) N m 2 C

-1 c) Js

-1 d) C m.

23. The total electric flux of the electric field E over any closed surface is equal to 1 / ε o times the net charge

enclosed by the surface. This is called ……………

a) Ohm’s law b) Gauss law c) Planck’s law d) Wien’s law

24. The electric field due to an infinite long straight charged wire is given by the equation E = …………..

a) λ / 2πεor b) r / 2πεo λ c) λ r / 2πεo d) 2πεor / λ

25. The electric field due to an infinite long charged plane sheet is given by the equation E = ………….

a) σ / 2εo b) σ / εo c) σ 2εo d) 2εo / σ

26. Electric field at any point in between two parallel sheets of equal and opposite charges is E = ……………..

a) σ / 2εo b) σ / εo c) σ 2εo d) 2εo / σ

27. The electric field at any point inside a uniformly charged spherical shell is ………….

a) q / 4πε o R2

b) q / 4πε o R c) q / 4πε o R3

d) zero

……………. Continued in page -2

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Page – 2

28. Electrostatic shielding is based on the fact that the electric field inside a conductor is ……………

a) maximum b) minimum c) zero d) infinite

29. The phenomenon of obtaining charges without any contact with another charge is called …………….

a) electrostatic induction b) electromagnetic induction c) static induction d) dynamic induction

30. The ratio of the charge given to the conductor to the potential developed in it is called ………….

a) reactance b) resistance c) inductance d) capacitance

31. The unit of capacitance is ………….

a) ohm b) henry c) tesla d) farad

32. A capacitor is a device to store …………..

a) current b) charges c) water d) oil

33. The number of electric lines of force originating from 1 coulomb charge is …………..

a) 1.129 X 10 12

b) 1.129 X 10 13

c) 1.129 X 10 11

d) 1.129 X 10 14

34. Non polar molecule is …………..

a) O2 b) H2 c) N2 d) all these

35. Polar molecule is …………..

a) O2 b) H2 c) N2 d) N2 O

36. The magnitude of the induced dipole moment p is directly proportional to ……………

a) E2 b) E c) 1 / E d) 1 / E

2.

37. The equation for the capacitance of a parallel plate capacitor with a dielectric is ………………..

a) εo εr A / εr ( d – t ) + t b) εo A / d c) εo A / εr ( d – t ) + t d) εo εr A / ( d – t ) + t / εr

38. When three capacitors C1 , C2 and C3 are connected in parallel, effective capacitance C p = …………

a) C1 C2 C3 / C1 + C2 + C3 b) C1 + C2 + C3 c) C1 + C2 + C3 / C1 C2 C3 d) C1 - C2 - C3

39. Greater the radius of a conductor, ………… is the charge density.

a) smaller b) larger c) zero d) infinity

40. Van de Graff generator produces a potential in the order of ………..volt.

a) 10 4

b) 10 8

c) 10 7

d) 10 3

41. Like charges ………… and unlike charges ……………. each other.

a) attract, repel b) attract, attract c) repel, repel d) repel, attract

42. The total charge on a body is given by the equation q = …………….

a) n / e b) n2 e c) ne d) 1 / ne

43. The permittivity of a medium is ……………

a) ε 0 / ε r b) ε 0 X ε r c) ε r / ε 0 d) 1 / ε 0 ε r

44. The total number of electric lines of forces originating from a point charge q in free space is N = …………

a) q ε 0 b) q / ε 0 c) ε 0 / q d) 1 / q ε 0

45. The equation for the torque on an electric dipole is ……………..

a) τ = p X E b) τ = p X E c) zero d) infinite

46. Electric potential energy is U =……………

a) F = q1 q2 / 4πε o r3 b) F = q1 q2 / 4πε o r

2 c) F = q1 q2 / 4πε o r d) F = q1 q2 / 4πε o r

4

47. The capacitances of a capacitor with and without a dielectric material are 90μF and 9μF. Then, εr is ……….

a) 90 b) 9 c) 10 d) 0.1

48. In micro wave oven, …………. are used.

a) IR rays b) UV rays c) visible light d) microwaves

49. An electric dipole contains charges +3 C and -3 C separated by 1 nm. The dipole moment is given by ………………..

a) 9 X 10 -9

Cm b) 3 X 10 -9

Cm c) 6 X 10 -9

Cm

d) 90 X 10 -9

Cm

50. The work done in moving a charge between any two points on an equipotential surface is …………

a) maximum b) minimum c) zero d) infinity

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Test Number : 2 Year : 2015- 2016 Onemark Test

+2 Physics UNIT : 2 CURRENT ELECTRICITY MARKS : 50

1. A charge of 180 C passes through a lamp in 3 minutes. The current through it is ……………….

a) 2 A b) 6A c) 3 A d) 1 A

2. A material through which the electric charges can flow freely is called ………………..

a) Insulators b) semiconductors c) conductors d) non-

conductors

3. The current is proportional to the ………. velocity.

a) drift b) average c) critical d) final

4. A toaster operating at 240 V has a resistance 60 ohm. The power is equal to ………… watt.

a) 4 b) 960 c) 0.25 d) 14,400

5. When two 4 ohm resistors are in parallel, the effective resistance is equal to ……….. ohm.

a) 2 b) 4 c) 8 d) 16

6. In the case of insulators, as the temperature increases, the resistivity ………………..

a) increases b) increases and then decreases c) becomes infinity d) decreases

7. If the resistance of the coil at 0oC is 1 ohm and α = 0.004/

oC, the resistance at 100

oC is …………...

a) 1.4 ohm b) 2.8 ohm c) 4.2 ohm d) 3.4 ohm

8. The current density has the unit …………….

a) A b) As-1

c) Am d) A m-2

9. The drift velocity acquired per unit electric field is called ………….

a) density b) resistivity c) conductivity d) mobility

10. mho m-1

is the unit of ……………………

a) density b) resistivity c) conductivity d) mobility

11. The resistivity of insulators is in the order of ………….. Ωm.

a) 10-8

to 1014

b) 10 8 to 10

14 c) 10

8 to 10

-14 d) 10

-2 to 10

4

12. In superconductors, the conductivity becomes …………….

a) maximum b) minimum c) zero d) infinity

13. The tolerance of silver, gold, red and brown rings in a carbon resistor are …………

a) % % % , % b) % %, % % c) %, % % % d) % % %, %

14. Four resistances 2Ω, 2 Ω, 4 Ω, 4 Ω are connected in series. The effective resistance is equal to ………….

a) 12 ohm b) ⅔ ohm c) 3 / 2 ohm d) 8 ohm

15. Kirchoff’s first law is a consequence of conservation of ……………….

a) currents b) charges c) voltages d) energy

16. Wheatstone’s bridge principle is used in ……………….

a) Planck’s law b) Faraday’s laws c) Kirchoff’s laws d) Joule’s law

17. Kirchoff’s second law is a consequence of conservation of …………..

a) currents b) charges c) voltages d) energy

18. The colours of a carbon resistor are red, green and orange. The value of resistance is ………….. kΩ

a) 25 b) 45 c) 20 d) 15

19. The balancing lengths are l1 =30 cm and l2 = 70 cm when the known resistance of 14 Ω is connected in the right gap of a

metre bridge. The value of unknown resistance is ………………..

a) 30 ohm b) 28 ohm c) 6 ohm d) 14 ohm

20. A lamp is operated at 240 V and the current is 0.25 A. The resistance value is ………… ohm.

a) 480 b) 320 c) 960 d) 160

21. The balancing lengths are l1 =510 cm and l2 = 340 cm in a potentiometer experiment. The ratio of the emfs is ………….

a) 2 / 3 b) 3 /1 c) 1 / 3 d) 3 / 2

22. The instrument used for measuring electrical power is called ………….

a) wattmeter b) voltmeter c) ammeter d) multimeter

23. The unit of electro chemical equivalent is ………………..

a) J / kg b) kg / C c) C / kg d) J / s

24. In voltaic cell, the electrolyte is ……………..

a) dil HCl b) dil HNO3 c) dil H2 SO4 d) NH4Cl

25. In Leclanche cell, at the cathode due to oxidation, Zn atom is converted into ………. ions.

a) Zn + + b) Cl --

c) Al+ + d) Cu + +

********* Continued – Page:2 ********


Page : 2

26. In lead acid accumulator, during discharge the emf falls to about ………….. volt.

a) 1.5 b) 2.2 c) 2.0 d) 1.08

27. The cell which is rechargeable is ……………..

a) secondary cell b) primary cell c) Leclanche cell d) Daniel cell

28. The internal resistance of the secondary cells is …………….

a) zero b) very high c) infinity d) very low

29. The mass of the substance liberated at an electrode is given by the equation ……………..

a) m = z I t b) m = zI / t c) m = It / z d) m = zt / I

30. In Daniel cell, the emf value is ……… volt.

a) 2.2 b) 2.0 c) 1.08 d) 1.5

31. Three resistors each of 2 Ω are connected in series with a cell of 12V. The potential drop across each resistor is …… volt.

a) 3 b) 2 c) 4 d) 6

32. A 10 Ω resistor is connected in series with a cell of emf 10V. A voltmeter is connected in parallel to the cell and it reads 9.9

V. The internal resistance of the cell is ………… ohm.

a) 0. 1 b) 1.01 c) 10.1 d) 101

33. The work done in moving a charge of 10 μ C between two points having a potential difference 100 V is ……….. joule.

a) 10 – 4

b) 10 – 5 c) 10

– 3 d) 10 - 6

34. If a current of 10 A flows through a resistor 10 k Ω, the power is ………….. watt.

a) 10 3 b) 10

6 c) 10

5 d) 10

2

35. The colour code numbers of yellow and grey in a carbon resistor are ……………..

a) 3 and 7 b) 4 and 8 c) 4 and 7 d) 3 and 8

36. The temperature at which a normal conductor is converted into a super conductor is called ………………..

a) neutral b) superconducting transition temperature c) curie d) inversion

37. The resistivity of copper is 2 X 10-8

Ωm. The conductivity of it is ……………. mho m-1

a) 5 X

b) 5 X

c) 5 X

d) 5 X

38. A copper wire of 10-6

m2 area of cross-section, carries a current density 1.6 X 10

6 Am-2 and n = 8 X 10

28 electrons / m

3.

The drift velocity is equal to …………………… ms-1

.

a) 1.25 X 10 -4 b) 1.25 X 10 -6 c) 1.25 X 10 -5 d) 1.25 X 10 -3

39. Two wires of same material and same length have resistances 16 Ω and 25 Ω. The ratio of the radii of the wires is ………

a) 4 / 5 b) 5 / 4 c) 3 / 5 d) 5 / 3

40. 1 kWh is equal to ………….. J.

a) X b) X c) X d) X

41. The external energy necessary to drive the free electrons in a definite direction is called as ………………..

a) electric potential b) electromotive force c) potential energy d) electric field

42. The rate of flow charges is called as ……………….

a) charge b) voltage c) current d) electric field

43. The direction of flow of positive charges in a conductor is called as the …………………...

a) charge b) voltage c) conventional current d) electric field

44. An electron of charge e in an electric field E experiences a force ……………...

a) F = E e b) F = E / e c) F = e2 E d) E

2 e

45. The unit of mobility is ……………….

a) m2 V-1 s-1 b) m V-1 s-1 c) m2 V s-1 d) m2 V-1 s

46. The quantity of charge passing per unit time through unit area is called as …………...

a) current b) potential difference c) current density d) electric

potential

47. The resistivity of semiconductors is in the order of ……………… Ωm.

a) to b) to c) to d) to

48. In Computers, ………….. can be used as memory or storage elements.

a) Insulators b) semiconductors c) super conductors d) conductors

49. The temperature coefficient of resistance of alloys is ……………...

a) zero b) very high c) infinity d) low

50. Germanium and silicon are called as ……………….

a) conductors b) semiconductors c) super conductors d) insulators

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Test Number : 3 Year : 2015- 2016 Onemark Test

+2 Physics Unit : 3 Effects of electric current Marks: 50

1. The electric iron works on the principle of ………… effect of current.

a) thermo electric b) Joule’s heating c) Peltier d) magnetic 2. The melting point of tungsten is ……………………… oC. a) 3000 b) 4000 c) 3380 d) 4380 3. Fuse wire has high resistance and ……………………… melting point. a) high b) low c) zero d) infinity

4. The thermo emf is maximum at a temperature called ……………………… temperature.

a) neutral b) inversion c) critical d) Kelvin 5. The unit of Peltier coefficient is ……………………… a) ampere b) ohm c) volt d) mho

6. Thomson effect is zero for ………………………

a) copper c) iron c) mercury d) lead 7. The unit of Thomson coefficient is ………………………

a) ampere b) volt / 0 C c) volt d) ohm 8. Thermopile is a device used to detect ………………………. a) light intensity b) sound intensity c) thermal radiations d) current 9. The equation for the magnetic induction at the centre of the current carrying circular ring is B = ………… a) µ0nI / 2a b) 2a / µ0nI c) µ0nI / a d) 2µ0nI / a 10. Tangent galvanometer works on the principle of ……………………… a) Ampere rule b) Maxwell’s right hand rule c) end rule d) tangent law

11. The reduction factor of T.G. is given by the equation ………………………

a) µ0nI / 2a b) 2a / µ0nI c) 2aBh/ µ0n d) µ0n / 2aBh

12. The magnitude of Lorentz force is F = ……………………… . a) Bqv cosθ b) Bqv tanθ c) Bqv secθ d) Bqv sinθ

13. The torque on a current carrying coil is maximum when the coil is ……………………… to the magnetic field. a) parallel b) perpendicular c) inclined at an angle d) none of the above 14. The deflection per unit voltage is called ………………………sensitivity of a galvanometer.

a) current b) voltage c) resistance d) conductance 15. An ideal voltmeter is which has ……………………… resistance. a) zero b) infinite c) minimum d) maximum 16. The product of the current and the loop area is called ……………………….

a) dipole intensity b) magnetic dipole moment c) permeability d) permittivity 17. The value of the gyromagnetic ratio is ……………………… C kg -1. a) 8.8 X 10 10 b) 9.27 X 10 -24 c) 4.8 X 10 10 d) 1.602 X 10 -19 18. The magnetic field in a moving coil galvanometer is the ……………………… magnetic field. a) perpendicular b) radial c) crossed d) non-uniform 19. The equation for force on a current carrying conductor in a magnetic field is F = ………

a) Bqv b) navd e c) Blv d) BIl

20. Lawrence devised ……………………… a) cyclotron b) van de graff generator c) ac generator d) galvaometer

21. For a given thermocouple, ……………………… temperature is a constant. a) neutral b) inversion c) critical d) Kelvin

22. Peltier effect is the converse of ……………………… effect. a) Thomson b) Ampere c) Seebeck d) Joule’s heating 23. In transformers, dynamos ……………………… effect is undesirable. a) Thomson b) Ampere c) Seebeck d) Joule’s heating 24. At the temperature of inversion, the thermo emf is …………………

a) minimum b) maximum c) zero d) infinity 25. Thermal energy may be used to produce an emf. This is called ……………………… effect. a) Joule’s law of heating b) photoelectric effect c) Peltier effect d) thermoelectric

………………… Continued ….. Page - 2


Page – 2

26. Joule’s law of heating is given by the equation H = ……………………… . a) I2 t b) V2Rt c) VIt d) IR2t 27. The alloy of nickel and chromium is called ……………………… . a) brass b) bronze c) silver d) nichrome 28. The relation between the thermo emf and the temperature is V = ………………………

a) α θ b) α θ + ½βθ2 c) ½βθ2 b) α θ + βθ2

29. The amount of heat absorbed or evolved at one junction in Peltier effect is H = ……………………… a) I2 t b) πIt c) VIt d) IR2t

30. Sn, Au, Ag, Zn, Cd, Sb show ……………………… effect. a) Negative Thomsn b) Positive Thomson c) Seebeck d) Joule’s heating 31. Bi, Ni, Pt, Co, Fe, Hg show ……………………… effect. a) Negative Thomsn b) Positive Thomson c) Seebeck d) Joule’s heating 32. Seebeck effect is a ……………………… process.

a) magnetic b) reversible c) irreversible d) electromagnetic 33. The thermo emf produced in Bi- Ag thermo couple is ……………………… Bi-Sb thermo couple.

a) larger than b) smaller than c) equal d) none of the above 34. Peltier coefficient depends on pair of metals in contact and the ……………………… of the junction. a) voltage b) resistance c) temperature d) none of the above 35. The unit of the magnetic induction is ……………………… . a) ampere b) ohm c) volt d) tesla 36. The magnetic induction due to infinitely long straight conductor carrying current is B = ……………………….

a) µ0I / 2a b) 2a / µ0nI c) 2aBh/ µ0n d) µ0I / 2πa

37. Around a current carrying conductor magnetic field is associated. This was observed by ……………………… a) Ampere b) Oersted c) Ohm d) Faraday 38. Tangent galvanometer is most sensitive for a deflection of ………………………. a) 300 b) 450 c) 600 d) 900 39. Tangent law is B = ……………………… .

a) BH Tan θ b) BH Sec θ c) BH Sin θ d) BH Cot θ 40. ……………………… law can be written as ∫ B . dl = µo Io .

a) Maxwell’s right hand b) Ampere’ circuital c) Seebeck d) Joule’s heating 41. When a charged particle moves in a circular path in a magnetic field, the time period is T = ………………………. a) Bq / 2m b) 2m / Bq c) 2πm / Bq d) Bq / 2πm

42. The torque on a rectangular coil of wire in a magnetic field is …………………… a) nBIA tanθ b) nBIA cosθ c) nBIA sinθ d) nBIA secθ 43. The deflection per unit current is called ……………………… sensitivity of a galvanometer. a) current b) voltage c) resistance d) conductance 44. The current sensitivity is given by ( θ / I ) = ……………………….

a) nCB / I b) nBAC c) BIl d) nBA / C

45. To convert a galvanometer in to an ammeter, a …… resistance is connected in parallel with the galvanometer. a) low c) infinite c) high d) very high

46. To convert a galvanometer in to a voltmeter, a ………… resistance is connected in series with the galvanometer. a) low b) very small c) high d) zero 47. Bohr magneton value is ……………………… Am2.

a) 8.8 X 10 10 b) 9.27 X 10 -24 c) 4.8 X 10 10 d) 1.602 X 10 -19 48. A current of 0.2 A flows through a circular loop of area 10 cm2. The magnetic dipole moment is ………… Am2 a) 9.27 X 10 -24 b) 8.8 X 10 10 c) 2 X 10 - 4 d) 2

49. In TG, a current of 1A produces a deflection of 300. The current that produces a deflection of 600 is ………… A. a) 2 b) 3 c) 5 d) 1 50. The resistance of the tungsten wire of a 100W,220V bulb is ……………………… ohm. a) 2.2 b) 220 c) 100 d) 484

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Test Number : 4 +2 Physics Year : 2015 - 2016 Onemark Test

Unit : 4 Electro magnetic induction and Alternating currents Marks : 50

01. Lenz law is in accordance with the law of conservation of ………………………

a) momentum b) energy c) voltage d) current

02. The self inductance of a straight conductor is …………………… a) infinity b) zero c) maximum d) minimum

03. The unit henry can also be written as …………………… a) H b) A c) V s A-1 d) m / s

04. Transformer works on ………………… currents only. a) direct b) alternating c) both direct and alternating d) steady

05. The part of the AC generator that passes the current from the coil to the external circuit is

a) armature b) slip rings c) field magnet d) brushes 06. The number of magnetic lines of forces crossing unit area in a magnetic field is magnetic …………………

a) flux b) induction c) permeability d) radiation 07. Electromagnetic induction was discovered by ……………….

a) Lenz b) Hertz c) Michael Faraday d) Oersted 08. Fleming’s right hand rule is also called as ………………… rule.

a) cork screw b) thumb c) end d) generator 09. The unit of self inductance is …………………...

a) H b) A c) V s A-1 d) m / s 10. The energy stored in an inductor is given by E = ……………….

a) ½ L2 Io b) L Io

2 c) L / Io2 d) ½ L Io

2 11. The equation for the mutual induction of two long solenoids is M = ………………..

a) µo N1 N2 A / l b) I / µo N1 N2 A c) µo N1 N2 A2 / l d) N1 N2 A / l

12. The induced emf by changing the area enclosed by a coil in a magnetic field is e = ………. a) EoSinωt b) – Blv c) - Bil d) - NBIA

13. When the plane of a coil is perpendicular to a magnetic field, the induced emf is ………….

a) maximum b) minimum c) zero d) infinity 14. AC generator is a device used for converting the mechanical energy into ………..

a) sound energy b) heat energy c) electrical energy d) light energy

15. If a number armature coils are used in the alternator, it is called as …………. alternator. a) single phase b) two phase c) three phase d) poly phase

16. Electro magnetic brakes use ……….. current . a) direct b) uni-directional c) eddy d) steady

17. Transformer works on the ……………… principle. a) electro static induction b) Huygens’s c) electromagnetic induction d) self induction

18. The ratio of the output power to the input power of a transformer is called ………………

a) velocity ratio b) mechanical advantage c) power loss d) efficiency 19. Eddy current losses are minimized by using a core made of ……………… an alloy of steel.

a) mumetal b) stelloy c) brass d) nichrome 20. The frequency of AC used for domestic power in India is …………..

a) 0 Hz b) 50 Hz c) 100 Hz d) 400 Hz

21. The average value of the AC over one complete cycle is ………….. a) 0 b) maximum c) minimum d) infinity

22. The relation between Irms and Io is ………………

a) Irms = Io / √ 2 b) Irms = Io X √ 2 c) Irms = Io / 2 d) Irms = √ Io / 2

23. In an AC circuit containing R only, the phase difference between current and voltage is …… a) 0 b) π / 2 c) π / 4 d) π

24. The inductive reactance XL is given by X L = ……… a) L ω b) 1 / L ω c) L / ω d) ω / L

25. A capacitor offers infinite resistance to ………… current. a) alternating b) direct c) varying d) sinusoidal

……………… Continued – page - 2


Page – 2

26. In RLC circuit, the instantaneous current is given by I = …………………. a) Io Sin ( ω t ± φ ) b) Io tan ( ω t ± φ ) c) Io cos ( ω t ± φ ) d) Io / √ 2

27. The equation for Q factor is given by Q = ………….. a) 1 /2 π √ L /C ) b) R ( √ L /C ) c) 1 /R ( √ L /C ) d) 1 /R L C

28. The average power consumed over a complete cycle is Pav = a) E rms I rms tan φ b) E rms I rms sin φ c) E rms I rms sec φ d) E rms I rms cos φ

29. Choke coil is used to control the current in an ………… circuit.

a) DC b) AC c) AC and DC d) steady 30. Choke coils are used in ………….. tubes which work on alternating currents.

a) filament b) oil c) fluorescent d) glass 31. The reactance of an inductor is ……………… proportional to the frequency.

a) first directly, then inversely b) first inversely, then directly c) directly d) inversely 32. Shell type cores are used to minimize ………………… losses.

a) eddy current b) power c) hysteresis d) flux

33. The number of magnetic lines of forces crossing a closed area is called magnetic …………….. a) flux b) induction c) permeability d) radiation

34. The selectivity or sharpness of a resonant circuit is measured by the …………… factor. a) safety b) power c) quality d) energy

35. The ratio of the voltage across a coil or capacitor to the applied voltage is called as …………factor. a) safety b) quality c) power d) energy

36. For normal frequencies, the Q factor lies between ……………... a) 1 and 10 b) 100 and 1000 c) 10 and 100 d) 0.1 and 10

37. For radio frequencies, air chokes are used. These chokes are called as ………… chokes. a) AF b) AF or RF c) R F or H F d) AF or HF

38. Whenever there is a change in the magnetic flux linked with a closed circuit, an emf is induced in it. This phenomenon is called …………………..

a) electro static induction b) action of points c) electromagnetic induction d) self induction

39. In Fleming’s right hand rule, the middle finger points the direction of the ………… a) motion of the conductor b) magnetic field c) induced current d) force

40. The property of the coil which enables to produce an opposing induced emf in it

when the current in the coil changes is called …………………… a) electro static induction b) self induction c) electromagnetic induction d) induction

41. If two coils are wound on a soft iron core one over the other , the mutual induction is ……………… a) zero b) infinity c) minimum d) very large

42. The induced emf is given by the equation e = …………… a) Eo sin ωt b) Eo cosωt c) Eo sec ωt d) Eo tan ωt

43. In fans, …………….. motors are used. a) electro static induction b) self induction c) electromagnetic induction d) induction

44. In step up transformers, the transformer ratio k is …………… than one. a) lesser b) greater c) smaller d) none

45. A power of 11kW is transmitted at 5.5kV through a transmission line of 1 ohm. The power loss = ……… a) 4 W b) 40 W c) 0.4 W d) 400 W

46. In an AC circuit containing C only, the phase difference between the current and the voltage is …………… a) 0 b) π / 2 c) π / 4 d) π

47. In an LCR circuit, at resonance, the impedance is ……………. and the current is maximum.

a) minimum b) maximum c) infinity d) zero 48. The rms value of the AC is ………….. times the peak value of the alternating current.

a) 1.414 b) 1.732 c) 0.707 d) 2.000 49. The direction of the eddy current can be noted by …………… a) Faraday’s laws b) Lenz’s law c) cork screw rule d) end rule

50. In a three phase AC generator, the emf’s of the coils differ by ………………... a) 120 0 b) 180 0 c) 90 0 d) 0 0

$$$$ Best wishes $$$$




TEST Number : 5 +2 Physics Year : 2015 - 2016 Onemark Test

+2 Physics Unit – 5 Electromagnetic waves and wave optics Marks : 50

1. Electromagnetic waves are discovered by ------------------

a) Planck b) J.C.Maxwell c) Newton d) Huygens

2. An accelerated charge is a source of ------------------

a) electromagnetic radiation b) heat radiation c) mechanical waves d) longitudinal waves

3. Electromagnetic waves are ----------------- in nature.

a) mechanical waves b) longitudinal waves c) transverse d) none of the above

4. The relation between the velocity of light C, µ0 and ε0 is given by the relation C = -----------------

a) 1 / √µ0 ε 0 b) √µ0 ε 0 c) √µ0 / ε 0 d) √ ε 0 / √µ0

5. Hertz produced electromagnetic waves of frequency ---------------

a) 5 X 10 9 Hz

b) 5 X 10

7 Hz c) 5 X 10

-7 Hz d) 5 X 10

-9 Hz

6. Electromagnetic waves cover a wide range of ----------------

a) directions b) waves c) frequencies d) none of the above

7. Atoms and molecules in an electric discharge tube give -------------- rays.

a) infra-red b) visible light c) UV d) X

8. The wavelength , the frequency and velocity of light are related by ----------------

a) c = γ λ b) c = γ / λ c) c = λ / γ d) c = γ / λ2

9. The frequency range of AM band is --------------

a) 54 MHz to 890 MHz b) 88 MHz to 108 MHz c) 530 kHz to 1710 kHz d) 88 kHz to 108 kHz

10. The frequency range of FM band is from ---------------

a) 54 MHz to 890 MHz b) 88 MHz to 108 MHz c) 530 kHz to 1710 kHz d) 88 kHz to 108 kHz

11. In Physiotherapy, ------------- lamps are used.

a) infra-red b) ordinary c) UVray d) X ray

12. The wavelengths of the sodium emission lines are ----------------- .

a) 5986 Ao and 5890 A

o b) 5896 A

o and 5980 A

o c) 5869 A

o and 5890 A

o d) 5896 A

o and 5890 A

o

13. The ----------- spectrum is used to identify the gas.

a) continuous b) band c) line d) none of the above

14. Incandescent solids, carbon arc lamp etc. give ------------- spectrum.


15. Using ------------- spectra, the molecular structure of the substance can be studied.


16. The example of line absorption spectrum is ------------ spectrum.

a) solar b) band c) line d) none of the above

17. The sun’s outer layer is called ----------------

a) photosphere b) ionosphere c) thermosphere d) chromosphere.

18. The type of delayed fluorescence is called -------------

a) Raman effect b) Tyndal effect c) Rayleigh scattering d) phosphorescence

19. According to corpuscular theory, light energy is the kinetic energy of the --------------

a) waves b) light source c) photons d) corpuscles

20. Huygens assumed that light waves are -------------- in nature.

a) longitudinal b) transverse c) mechanical d) stationary

21. The energy of each photon is given by the equation --------------

a) E = mc2 b) E = h γ c) E = ma d) E = mv

22. The scattering of sunlight by the molecules of the earth’s atmosphere is called --------------- scattering.

a) Raman b) Tyndal c) Rayleigh d) Einstein

23. The scattering of light by the colloidal particles is called --------------- effect.


24. In industry, ---------------- spectroscopy is applied to study the properties of the materials.


25. The locus of the particles having the same state of vibration is called as -----------------

a) wave b) corpuscle c) wavefront d) photon

******* Continued ……….. Page - 2


Page – 2

26. A linear source of light will give rise to ---------------- wavefront.

a) spherical b) plane c) cylindrical d) elliptical

27. -------------- principle helps us to locate the position and the shape of the wavefront.

a) Raman b) Tyndal c) Rayleigh d) Huygen

28. In reflection of light, the angle of incidence = the angle of ------------

a) refraction b) polarisation c) reflection d) diffraction

29. For total internal ----------- to take place, light must travel from denser medium to rarer medium.


30. The equation of bandwidth of interference fringes is β = ---------------

a) λD / d b) λD d c) λ /D d d) λd / D

31. An important application of interference in thin films is the formation of -------------- rings.

a) Raman’s b) Tyndal’s c) Rayleigh’s d) Newton’s

32. The radius of the nth

dark ring equation is ------------.

a) r n2 = ( n R λ )

2 b) r n = n

2 R λ c) r n = ( n R λ )

½ d) r n = n R

2 λ

33. The amount of bending in diffraction depends on the ----------------

a) size of the obstacle b) volume of the obstacle c) size of the obstacle d) wavelength of the incident

wave.

34. In Fresnel diffraction, the incident wavefront is either -------------------.

a) spherical or ellipse b) plane or ellipsoid c) spherical or cylindrical d) elliptical

35. Using spectrometer, ------------------ diffraction can be observed.

a) Fraunhofer b) Raman c) Tyndal d) Rayleigh

36. The combined width of a slit and a ruling is called -----------------

a) grating element b) prism element c) polaroid element d) element

37. In a plane diffraction grating, λ = ----------------

a) nm / Sin θ b) Sin θ / nm c) nm / Sin θ d) ( nm Sin θ )1/2

38. The phenomenon of ---------------- proves that light waves are transverse.


39. The plane perpendicular to the plane of vibration is called plane of ------------------


40. A device that produces a plane ------------- light is called polariser.

a) polarized b) reflected c) refracted d) diffracted

41. The angle of incidence at which the reflected beam is completely plane polarised is called angle of -----------------

a) refraction b) diffraction c) reflection d) polarisation

42. The equation for Brewster’s law is µ = ---------------

a) sin i p b) cot i p c) tan i p d) cos i p

43. The polarising angle for glass is -------------------

a) 57. 5 o

b) 56. 5 o

c) 32. 5 o

d) 50. 7 o

44. The pile of plates uses the polarisation by ---------------------- phenomenon.


45. The double refraction phenomenon was discovered by ------------------

a) Bartholinus b) Malus c) Nicol d) Young

46. Crystals like mica, topaz etc. having two optic axes are called ------------------

a) uni-axial crystals b) multi-axial crystals c) biaxial crystals d) none of the above

47. The refractive index for Canada balsam cement is -------------- for both the rays.

a) 1.486 b) 1.658 c) 1.550 d) 1.333

48. H polaroids use a thin film of --------------------

a) herapathite crystals b) polyvinyl alcohol c) Canada balsam d) Na Cl

49. Polaroids are used as ----------------------- glasses.

a) moon b) star c) planet d) sun

50. In an EM wave, the electric and the magnetic field vectors are at --------------- to each other and to the direction of

propagation.

a) 45 0

b) 90 0

c) 180 0

d) 145 0

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+ 2 Physics * 2014-2015 * Unit – 6 Atomic Physics * Maximum marks : 90

1. At atmospheric pressure, air and other gases are …………… conductors of electricity.

a) good b) semi c) poor d) rich

2. Electric current may be passed through a gas by allowing ……………. to pass through them.

a) light b) infra-red c) X –rays d) none of the above

3. Electrons were discovered by ………………

a) Millikan b) Goldstein c) Einstein d) Thomson

4. …………………… is an arrangement to study the conduction of electricity through gases.

a) X-ray tube b) Coolidge tube c) discharge tube d) GM counter

5. In a discharge tube, the potential difference applied between the two electrodes is ………………

a) 10000 V b) 20000 V c) 60000 V d) 50000 V

6. In a discharge tube, the discharge of electricity through gases starts at a pressure of about …………

a) 100 mm of Hg b) 1 mm of Hg c) 10 mm of Hg d) 0.01 mm of Hg

7. In a discharge tube, the positive column is produced at a pressure of about ………………


8. In a discharge tube, Crooke’s dark space is produced at a pressure of about ……………


9. Cathode rays travel with a velocity up to ………………. of the velocity of light.

a) (1 /100)th

b) (1 /10)th

c) (1 /1000)th

d) (1 /10000)th

10. Canal rays were discovered by ……………….in the year 1886.


11. In 1887, ………………… measured the specific charge of the cathode ray particles.


12. If V is the potential difference between the two plates and d is the distance between them, then E = …

a) V d b) d / V c) V / d d) V2 / d

13. e / m value of the electron is …………………..

a) 1.7592 X 1011

C kg-1

b) 1.7592 X 1011

C kg c) 1.602 X 10

19 C kg

-1 d) 1.602 X 10

-19 C kg

-1

14. Millikan’s experiment is used for the measurement of ………… of the electron.

a) density b) specific charge c) mass d) charge

15. In Millikan’s experiment, the potential difference applied between the two electrodes is ………

a) 10000 V b) 20000 V c) 60000 V d) 50000 V

16. The net downward force acting on the oil drop = ……………..

a) zero b) maximum c) minimum d) ⅓ X 4 π a3 ( ρ - ζ ) g

17. In Millikan’s experiment, the charge of the electron q = ……………

a) ⅓ X 4 π a3 ( ρ - ζ ) g b) 4 π a3 ( ρ - ζ ) g c) (⅓ )π a3 ( ρ - ζ ) g d) zero

18. In Millikan’s experiment, the charge value of the electron = ………………….

a) 1.7592 X 1011

C kg-1

b) 1.7592 X 1011

C kg c) 1.602 X 10

19 C kg

-1 d) 1.602 X 10

-19 C kg

-1

19. The concept of atoms was proposed by ………………

a) Bohr b) Thomson c) Dalton d) Prout

20. Prout suggested that all elements are made up of atoms of …………………

a) carbon b) helium c) hydrogen d) nitrogen

21. Atom is a sphere of positive charge in which the electrons are embedded. This was suggested by ..…

a) Bohr b) Thomson c) Dalton d) Prout

22. In the case of hydrogen atom, Thomson’s model gives only one spectral line of about ……………

a) 3300 Ao

b) 2300 Ao c) 1300 A

o d) 4300 A

o

23. The scattering of α particles provide useful information about the structure of the ………………..

a) atom b) hydrogen c) CO 2 d) oxygen

…………… Continued in Page - 2


Page - 2

24. The diameter of the atom is about …………..

a) 10-20

m b) 10-10

m c) 10-14

m d) 1010

m

25. The diameter of the nucleus is about …………….

a) 10-20

m b) 10-10

m c) 10-14

m d) 1010

m

26. According to electromagnetic theory, an accelerated electric charge must radiate energy in the form of ……

a) light b) infra-red rays c) X –rays d) electromagnetic waves

27. An electron revolving in the stationary orbit does not radiate ………...

a) lepton b) energy c) meson d) particle

28. According to Bohr’s quantization condition, the angular momentum of the electron = ……………

a) h / 2 b) 2 π / n h c) nh / 2π d) 2π nh

29. The radius of the nth

orbit of the electron is proportional to the square of the ……… quantum number

a) spin b) principal c) magnetic d) angular momentum

30. Bohr radius value r1 = …………………

a) 0.63 Ao b) 0.83 A

o c) 0.53 A

o d) 0.43 A

o

31. The energy of the electron En = ……………..

a) - z2me

4 / 8ε0

2n

2h

2 b) z

2me

4 / 8ε0

2n

2h

2 c) n

2h

2ε0 / π mze

2 d) - z

2me

4 / 4ε0

2n

2h

2

32. 1 electron volt = ……………… J

a) 1.602 X 1019

b) 1.602 X 10-19

c) 9.11 X 10-31

d) 9.11 X 10 31

33. Rydberg’s constant value R = ……………….

a) 1.094 X 107

m-1

b) 1.602 X 109 c) 1.602 X 10

-19 d) 9.11 X 10

-31

34. The spectral lines of Lyman series of hydrogen atom lie in the ………… region.

a) UV b) Visible c) infra - red d) gamma

35. The spectral lines of Balmer series of hydrogen atom lie in the ……………..


36. The spectral lines of Paschen series of hydrogen atom lie in the ……………….


37. The spectral lines of Brakett series of hydrogen atom lie in the ………………


38. The spectral lines of Pfund series of hydrogen atom lie in the …………..


39. The wavelengths of D1 and D2 lines of sodium are .................

a) 5809Ao ,5896 A

o b) 5986A

o ,5980 A

o c) 5689A

o ,5690 A

o d) 5896A

o ,5890 A

o

40. The energy required to raise an atom from its normal state into an excited state is called ……. energy.

a) excitation potential b) potential c) kinetic d) stellar

41. The value of ionization potential energy for hydrogen atom is …………

a) 13.6 eV b) 30.6 eV c) 3.4 eV d) 10.2 eV

42. The fine structure of spectral lines can not be explained by ………… theory.

a) Raman b) Newton c) Bohr d) Huygens

43. It is found that when magnetic field is applied to the atom, each of the spectral line is split into

several lines. This effect is called ……… effect.

a) Stark b) Zeeman c) Raman d) Tyndal

44. According to Sommerfeld’s atom model, for any principal quantum number n, there are n possible

sub-shells, out of which one is circular and the remaining two are ……………. in shape.

a) elliptical c) semi-circular c) square d) rectangle

45. X-rays were discovered by ……………

a) Raman b) Newton c) Roentgen d) Huygens

46. X-rays are electromagnetic waves of short wavelength in the range of ……………

a) 0.5 Ao to 10 A

o b) 0.5 A

o to 100 A

o c) 0.5 A

o to 1000 A

o d) 10 A

o to 100 A

o

………… Continued in Page - 3


Page – 3

47. Roentgen was awarded Nobel prize in 1901 for the discovery of …………….

a) gamma b) UV c) beta d) X-rays

48. When fast moving electrons are suddenly stopped by a metallic target, ……… are produced.

a) gamma rays b) UV rays c) X-rays d) beta rays

49. In Coolidge tube, a high potential of about …………… is applied between filament F and the target T.

a) 10000 V b) 20000 V c) 60000 V d) 50000 V

50. X-rays are of ……………. types.

a) 3 b) 4 c) 2 d) 5

51. X-rays having wavelength of 4Ao or above are called ………………

a) hard X –rays b) soft X – rays c) medium X – rays d) gamma rays

52. X-rays having low wavelength in the order of 1Ao are called ……………

a) hard X –rays b) soft X – rays c) medium X – rays d) gamma rays

53. The penetrating power of hard X-rays is …………….

a) low b) very low c) high d) zero

54. When X-rays fall on certain metals, they liberate …………………

a) protons b) photons c) electrons d) mesons

55. To detect and measure the intensity of the X-rays, ………………. chamber is used.

a) Thomson b) Bohr c) ionization d) Dalton

56. Any plane containing an arrangement of atoms is known as a …………… plane.

a) lattice b) crystal c) metal d) molecular

57. Laue experiment is used to produce diffraction in ………………...


58. Bragg’s law is ……………….

a) 2d tanθ = λ b) d Sinθ = n λ c) 2d Sin θ = n λ d) 2d Cos θ = n λ

59. Bragg’s spectrometer is used to measure the wavelength of ……………


60. The minimum wavelength of the radiation emitted in continuous X-ray spectra λ min = ………

a) 12400Ao / V b) 1240 A

o / V c) 124 A

o / V d) 124000A

o / V

61. When an electron jumps from M shell to the K shell, it gives ………in the case of characteristic X-rays.

a) Lβ line b) K β line c) Kα line d) Mβ line

62. The frequency of the spectral line in the characteristic X-rays is directly proportional to the square of the

atomic number of the element. This is called ………………….

a) Moseley’s law b) Stokes’s law c) Newton’s law d) Planck’s law

63. …………. has led to the discovery of new elements like technetium, hafnium etc.

a) Planck’s law b) Stokes’s law c) Newton’s law d) Moseley’s law

64. In normal population, the number atoms in the ground state is ………… than the excited state.

a) smaller b) lesser c) greater d) lower

65. In population inversion, the number atoms in the ground state is …………. than the excited state.

a) higher b) lesser c) greater d) more

66. The life time of atoms in the excited state is normally ……………..

a) 10-6

second b) 10-3

second c) 10-8

second d) 10-10

second

67. The life time of atoms in the metastable state is normally ……………

a) 10-6

second b) 10-3

second c) 10-8

second d) 10-10

second

68. A ruby is a crystal of ……………. , in which of Al+3

ions are replaced by Cr+3

ions.

a) P2O5 b) Al2O6 c) Al2O2 d) Al2O3

69. The wavelength of green colour is ……………

a) 7500 Ao b) 5500 A

o c) 6943 A

o d) 6328A

o

…………… Continued in Page - 4


Page -4

70. The wavelength of red colour is ………………

a) 7500 Ao b) 5500 A

o c) 6943 A

o d) 6328A

o

71. He-Ne laser system consists of a quartz discharge containing helium and neon in the ratio of ….. at

a pressure of about 1 mm of Hg.

a) 4 : 1 b) 1 : 2 c) 1 : 4 d) 2 : 1

72. The wavelength of the emitted photon in the He-Ne laser system ……………..

a) 7500 Ao b) 5500 A

o c) 6943 A

o d) 6328A

o

73. The beam that is used in endoscopy is ……………….

a) laser b) maser c) ordinary light d) microwaves

74. The beam that is used in holography is ……………


75. The ……… action is based on the principle of population inversion followed by stimulated emission.


76. The ……………. ions are used as maser materials.

a) diamagnetic b) paramagnetic c) ferromagnetic d) aluminum

77. Practical maser materials are often ………………….. ions doped as impurities in ionic crystals.

a) chromium b) sodium c) potassium d) calcium

78. ……………. is used in molecular spectroscopy.


79. In optical fiber, ……………. laser is used.

a) metal b) non-conducting c) semiconductor d) optical

80. The ratio of the radii of the first three orbits of an atom is ……………

a) 1 : 2 : 3 b) 1 : 3 : 5 c) 1 : 4 : 9 d) 1: 3 : 9

81. The cathode rays are a stream of …………….

a) protons b) photons c) electrons d) mesons

82. According to Bohr’s postulates, ……………. quantity take discrete values.

a) energy b) momentum c) radius d) angular momentum

83. For hydrogen atom, the minimum energy required to remove an electron from the first orbit to

the outermost orbit is …………. eV.

a) 13.6 b) 10.2 c) 5.4 d) infinity

84. According to Rutherford atom model, atoms will give only …………… spectrum.

a) continuous b) line c) band d) line absorption

85. The elliptical orbits of electron in the atom were proposed by …………….

a) Thomson b) Sommerfeld c) Roentgen d) Huygens

86. X ray is the phenomenon of conversion of kinetic energy into ……………

a) radiation b) potential energy c) magnetic d) electrostatic energy

87. The chromium ions doped in the ruby rod absorbs …………… light.

a) red b) blue c) green d) yellow

88. Canal rays travel …………. than the cathode rays.

a) slower b) faster c) higher speed d) none of the above

89. The spectra of alkali metals such as K, Na etc cannot be explained by ……………. atom model.

a) Thomson b) Sommerfeld c) Roentgen d) Huygens

90. In laser, all the photons are in …………. with each other.

a) phase b) face c) pace d) base

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+2 PHYSICS Test Number : 7 Year : 2014– 2015 Time : 1 Hour

Unit : 7 Dual nature of radiation , Matter and Relativity Marks: 50

1.The emission electrons from the metal surfaces when the electromagnetic radiations fall on them is called …….

a) Photo electric effect b) Tyndal effect c) Raman effect d) Zeeman effect

2.Photoelectric effect phenomenon was discovered by …………………

a) Newton b) Maxwell c) Hertz d) Huygens

3.Hallwachs experiment set-up is used to study …………….

a) Photo electric effect b) Tyndal effect c) Raman effect d) Zeeman effect

4.Photoelectric current is ………. proportional to the number of photoelectrons emitted per second.

a) inversely b) directly c) first directly and then inversely d) none of the above

5.The minimum negative potential given to the anode for which photoelectric current becomes zero is called …….

a) retarding potential b) increasing potential c) stopping potential d) critical potential

6.If m is the mass of the photoelectron and v max is the velocity, then the kinetic energy of the electron is ………

a) m v max 2

b) ( ½ )v max 2 c) (½ )m

2 d) (¼) m v max

2

7.The stopping potential depends upon the ……….. of the fastest electron.

a) velocity b) charge c) mass d) density

8.For a given frequency of the incident radiation, the stopping potential ………..of its intensity.

a) depends b) is independent c) is proportional d) none of the above

9.The minimum frequency of the incident radiation below which the photoelectric effect is not possible is called ….

a) threshold frequency b) critical value c) critical mass d) critical density

10.Photoelectric emission is an …………………. process.

a) slow b) fast c) instantaneous d) very slow

11.The maximum kinetic energy of the photoelectrons is ………. proportional to the frequency of incident radiation.

a) inversely b) directly c) first directly and then inversely d) none of the above

12.The electromagnetic theory of light could not explain …………….. effect.

a) Tyndal b) Raman c) Stark d) photoelectric

13.According to the quantum theory, light is emitted in the form discrete bundles of energy called ……………..

a) waves b) corpuscles c) photons d) mesons

14.The energy of the photon is E = ………..

a) mc2

b) hγ c) mgh d) (½) mv2

15.In the phenomenon interference, the photons behave like a …………..

a) waves b) corpuscles c) photons d) mesons

16.In the phenomenon like emission, the photon behaves like a …………..

a) waves b) corpuscles c) photons d) particles

17.In 1905, Einstein, successfully applied …………theory to photoelectric effect.

a) waves b) corpuscular c) quantum d) mesons

18.The energy spent in releasing the photoelectrons from a metal surface is called ……………

a) kinetic energy b) potential energy c) work function d) excitation energy

19.Einstein’s photoelectric equation is ……………………..

a) hγ – hγ0 = ½ m v max 2 b) hγ = ½ m v max

2 c) hγ – hγ0 = m v max

2 d) hγ0 = ½ m v max

2

20.The photoelectric cell is a device which converts light energy into ………… energy.

a) chemical b) kinetic c) potential d) electric

21.Caesium oxide has …….. work function to give large number of photoelectrons.

a) high b) low c) large d) zero

22.The three types of the photoelectric cells are of …………. types.

a) 2 b) 5 c) 4 d) 3

23.Photoelectric cells are used to reproduce sound in …………….

a) solar heater b) bulbs c) furnaces d) cinematography

24.Photoelectric cells are used to control the temperatures of ………….

a) solar heater b) bulbs c) furnaces d) stars

25.Photoelectric cells are used to study the spectra and the temperatures of …………….

a) solar heater b) bulbs c) furnaces d) stars


26.In opening and closing of doors ………. cells are used.

a) primary b) secondary c) photo electric d) Daniel

27.In burglar and fire alarms ……………… cells are used.

a) primary b) secondary c) photo electric d) Daniel

28.Matter in motion must be accompanied by waves called …………… waves.

a) transverse b) longitudinal c) de Broglie d) stationary

29.The de Broglie wavelength of the de Broglie waves is λ = ……………..

a) λ = h / v b) λ = h / mv c) λ = h / mv2 d) λ = h / 2mv

30.The de Broglie wavelength of the de Broglie waves is λ = 12.27 A0 / ( ……)

1/2

a) E b) P c) V d) h

31.The stationary orbits of electrons are those in which orbital circumference( 2πr) is an integral multiple of. …

a) energy b) wave number c) frequency d) de Broglie wavelength

32.The electron microscope is used for ………….. small objects.

a)splitting b) magnifying c) destroying d) producing

33.The resolving power of the microscope is limited by the ……………. of the radiation.

a) energy b) wavelength c) momentum d) type

34.In an electron microscope, electrons are accelerated by a potential difference of about …………..volt.

a) 20000 V b) 50000 V c) 60000 V d) 10000 V

35.The wavelength of the electron beam is about ……….

a) 5 X 10 -10

m b) 5 X 10 -12

m c) 5 X 10 -7

m d) 5 X 10 -9

m

36.The wavelength of the electron beam is ………. times smaller than that of the visible light.

a) 10 5 b) 10

50 c) 10

10 d) 10

15

37.In medicine and biology, the electron microscope is used study …………

a) virus b) crystal structure c) bones d) ions

38.Structure of crystals can be studied using ……………… microscope.

a) optical b) ordinary c) electron d) proton

39.In Einstein’s view, there is no absolute space and all motions are ………..

a) relative b) independent c) slow d) fast

40.The special theory of relativity was profounded by …………….

a) Newton b) de Broglie c) Kepler d) Einstein

41.In classical mechanics, the mass of the body is absolute and ………….

a) variable b) zero c) constant d) infinite

42.A system of co-ordinate axes that defines the position of a particle in three dimensional space is called….

a) frame of reference b) inertial frame c) time dilation d) length contraction

43.When the bodies in a frame of reference obey Newton’s law of inertia, the frame is called ……….

a) frameless b) inertial frame c) non-inertial d) length contraction

44.When the bodies in a frame of reference do not obey Newton’s law of inertia, the frame is called ……….

a) frameless b) inertial frame c) non-inertial d) length contraction

45.The simplest frame of reference is the …………….. co-ordinate system in which the position of a particle

is specified by 3 co-ordinates.

a) Newton b) de Broglie c) Cartesian d) Einstein

46.The velocity of light in free space is a …………….. in all frames of references.

a) variable b) zero c) constant d) infinite

47.A circular object will appear as an ………… for a fast moving observer.

a) circle b) ellipse c) square d) rectangle

48.The clocks in the moving space ships will appear to go ……………. than the clocks on the earth.

a) faster b) very faster c) slower d) none of the above

49.The relation between the mass of a body at rest ( m0 )and the mass of the same body moving with

velocity v as m = ………

a) m = mo / ( 1 – v2 /c

2 ) b) m = mo / (v

2 /c

2 ) c) m = mo d) m = mo / ( √ 1 – v

2 /c

2 )

50.Einstein’s mass – energy equivalence is given by ………………….

a) E = mC / 2 b) E = m/ C2 c) E = m C d) E = m C

2

@@@@@@@ Best wishes @@@@@@@


+2 Physics Test Number : 8 Year : 2014 – 15 Time : 1½ Hours

UNIT : 8 NUCLEAR PHYSICS MARKS : 100

1. The atomic nucleus was discovered by ----------------- in 1911.

a) Rutherford b) Thomson c) Bohr d) Chadwick.

2. Protons and neutrons inside the nucleus are called ------------------

a) nuclear forces b) atomic number c) nucleons d) neutral particles.

3. The mass of the proton is --------------- times greater than the mass of the electron.

a) 1386 b) 1886 c) 1836 d) 3186.

4. The total number of protons and neutrons is called ---------------- number.

a) atomic b) mass c) neutron d) quantum

5. The total number of protons or the total number of electrons is called ----------------- number.

a) atomic b) mass c) neutron d) quantum

6. The atoms of the same element with same atomic number but different mass number are called ----------------.

a) isotones b) isobars c) isotopes d) none of the above.

7. The isotopes have different number of --------------------.

a) electrons b) photons c) protons d) neutrons.

8. The --------------- have identical chemical properties.

a) isotones b) isomers c) isotopes d) none of the above.

9. The atoms of different elements with same mass number but different atomic number are called ----------.

a) isotones b) isobars c) isotopes d) none of the above.

10. 8O16

, 7N16

are called --------------------

a) isotones b) isomers c) isotopes d) isobars

11. The isotones of different elements have same number of --------------------

a) electrons b) photons c) protons d) neutrons

12. The empirical formula for the nuclear radius is -------------------------

a) R = ro A⅓

b) R = ro / A⅓

c) R = A⅓

/ ro d) none of the above.

13. One fermi is ---------------

a) 10 -15

m b) 10 -16

m c) 10 -10

m d) 10 -16

m

14. The mass of one nucleon is approximately ----------------------- kg.

a) 1.66 X 10 – 27

b) 9.11 X 10 – 31

c) 6.623 X 10 – 34

d) 1.602 X 10 – 19

15. The nuclear density value is ---------------- kg m -3

.

a) 1.816 X 10 17

b) 9.11 X 10 – 31

c) 6.623 X 10 – 34

d) 1.816 X 10 17

16. The charge value one proton is ------------------ C.

a) 1.66 X 10 – 27

b) 9.11 X 10 – 31

c) 6.623 X 10 – 34

d) 1.602 X 10 – 19

17. One twelfth of the mass of the carbon atom ( 6C12

is called --------------

a) 1 amu b) binding energy c) mass defect d) critical mass

18. 1 amu = ----------------- kg.

a) 1.66 X 10 – 27

b) 9.11 X 10 – 31

c) 6.623 X 10 – 34

d) 1.602 X 10 – 19

19. The mass of one proton = --------------- amu.

a) 1.009665 b) 1.07772 c) 1.007276 d) 1.008665

20. The mass of one neutron = ------------------ amu.

a) 1.009665 b) 1.007772 c) 1.007276 d) 1.008665

21. 1 eV = --------------- J.

a) 1.66 X 10 – 27

b) 9.11 X 10 – 31

c) 6.623 X 10 – 34

d) 1.602 X 10 – 19

22. The energy equivalent of 1 amu is ----------------- .

a) 913 MeV b) 931 MeV c) 319 MeV d) 193 MeV

23. The binding energy = --------------- X C 2.

a) 1 amu b) binding energy c) mass defect d) critical mass.

24. In BE / A curve, for A < 20, there exists peaks to those nuclei whose mass numbers are multiples of ---------------.

a) 6 b) 8 c) 4 d) 2

25. Binding energy per nucleon of the iron nucleus is ---------------- .

a) 7.6 MeV b) 8.5 MeV c) 8.8 MeV d) 931 MeV.

…………… Continued in Page -2


Page – 2

26. BE/A is about ---------------- for nuclei having mass numbers ranging between 40 and 120.

a) 7.6 MeV b) 8.5 MeV c) 8.8 MeV d) 931 MeV

27. BE/A is about ----------- for uranium.

a) 7.6 MeV b) 8.5 MeV c) 8.8 MeV d) 931 MeV

28. Mass spectrometer is used to find --------------------

a) light spectrum b) charge c) isotopic masses d) velocity

29. In Bainbridge mass spectrometer, ---------------- arrangement selects ions of a particular velocity to come out.

a) velocity selector b) cyclotron c) slit d) cathode

30. The force between the nucleons is called --------------- .

a) gravitational force b) electrostatic force c) centripetal force d) nuclear force

31. Nuclear force is ---------- times stronger than the gravitational force.

a) 10 40

b) 10 30

c) 10 10

d) 10 15

32. Nuclear force is strong between nucleons which are less than ------------------ m.

a) 10 5 b) 10

15 c) 10

-10 d) 10

-15

33. Nuclear force is due to the continuous exchange of the particles called ----------------- .

a) leptons b) baryons c) photons d) mesons

34. Radioactivity was discovered by --------------- in the year 1896.

a) Marie Currie b) Pierre Curie c) Rutherford d) Henri Becquerel

35. Radium and polonium were discovered by ------------------------

a) Marie Currie b) Fajans c) Rutherford d) Henri Becquerel

36. The phenomenon of spontaneous emission of α β , γ rays by elements having atomic number greater than

82 is called --------------

a) radioactivity b) induced radioactivity c) photo electricity d) ionisation

37. The ---------------- is unaffected by any external agent like pressure, temperature and electric, magnetic fields


38. An α particle is a -------------- nucleus.

a) hydrogen b) nitrogen c) oxygen d) helium

39. The ionising power of α rays is -------------- times greater than the β rays.

a) 1000 b) 10 c) 100 d) 10,000

40. The displacement laws were framed by ------------------- .

a) Marie Currie b) Soddy and Fajans c) Rutherford d) Henri Becquerel

41. Radium is converted into radon in the ------------------- decay.

a) α b) β c) γ d) δ

42. In β decay , the atomic number increases by ---------------- .

a) 4 b) 2 c) 1 d) 5

43. Theoretically, ---------------- time is needed for the disintegration of all the radioactive atoms.

a) infinite b) zero c) minimum d) fractional

44. The relation between half life period and the decay constant is T = --------------

a) 0.6931 / 2 λ b) 0.6931 / λ c) 0.6931 / 3 λ d) 0.6931 / 4 λ

45. The mean life period is ------------------- proportional to the decay constant.

a) directly b) directly and inversely c) inversely d) none of the above

46. The rate at which the radioactive atoms decay is called ------------------

a) Nuclear fission b) Nuclear fusion c) activity d) none of the above

47. 1 becquerel = ------------------disintegration / second

a) 10 b) 1000 c) 100 d) 1

48. The activity of a radioactive substance is generally expressed in -----------------

a) newton b) henry c) curie d) joule

49. Neutron was discovered by ----------------

a) Newton b) Henry c) Curie d) Chadwick

50. 4 Be 9 + 2 He

4 → 6 C

12 + ------------

a) o n 1 b) 1 H

1 c) 1 H

2 d) 2 He

4



Page – 3

51. Neutrons are the constituent particles of all nuclei, except ----------------

a) 1 H 3 b) 1 H

1 c) 1 H

2 d) 2 He

4

52. The half life period of an isolated neutron is ----------------- minutes.

a) 10.1 b) 3 c) 13 d) 7

53. The energy of a slow moving neutron is ----------------- .

a) 0 to 1000 eV b) 0.5 MeV to 10 MeV c) 2 MeV d) 5 MeV

54. The energy of a fast moving neutron is -------------------

a) 0 to 1000 eV b) 0.5 MeV to 10 MeV c) 2 MeV d) 5 MeV

55. Induced radioactivity was discovered by ------------------ in the year1934.

a) Rutherford & Soddy b) Chadwick c) Thomson d) Irene Curie & Joliot

56. Positron is emitted only in ----------------- radioactivity.


57. The half life period of 7 N 13*

is -------------- minutes.

a) 10.1 b) 3 c) 13 d) 7

58. The half life period of 15 P 30*

is ---------------- minutes.

a) 10.1 b) 3 c) 13 d) 7

59. Radio-isotopes can be obtained using the particle accelerator like ---------------

a) GM counter b) Cyclotron c) Mass spectrometer d) Radio

60. Co 60*

is used in the treatment of --------------------

a) checking blood circulation b) cancer c) anaemia d) thyroid glands

61. Na 24*

is used in the treatment of -----------------------


62. I131*

is used in the treatment of ------------------

a) checking blood circulation b) cancer c) anaemia d) thyroid glands.

63. Fe 59*

is used in the treatment of ------------------


64. P 32*

is used in the treatment of ----------------------

a) skin diseases. b) cancer c) anaemia d) thyroid glands.

65. The ratio of C14

and C12

atoms in atmosphere is --------------.

a) 1 : 106

b) 106 : 1 c) 1 : 10

15 d) 1 : 10

16

66. The half life period of the radio – carbon is ------------------ .

a) 6550 years b) 7550 years c) 5570 years d) 7570 years

67. The genetic damage is caused by --------------- rays.

a) α b) β c) γ d) δ

68. If the radiation exposure is --------- , it may cause diseases like leukemia.

a) 300 R b) 600 R c) 100 R d) 250 mR

69. If the radiation exposure is -------------- , it causes death.

a) 300 R b) 600 R c) 100 R d) 250 mR

70. Safe limit of receiving the radiations is --------------- per week.

a) 300 R b) 600 mR c) 100 R d) 250 mR

71. The intensity of the radioactive radiation is measured by the device -------------- .

a) GM counter b) Cyclotron c) Mass spectrometer d) Radio

72. The most probable mass numbers of the fission fragments lie between ------------------.

a) 110 to 150 b) 80 to 110 c) 95 and 140 d) 40 to 120

73. When 92 U 235

is bombarded with a neutron , the value of the energy released is ------------.

a) 1000 eV b) 10 MeV c) 200 MeV d) 0.025 eV

74. Niels Bohr and John A. Wheeler explained the nuclear fission by ----------------- model.

a) Thomson atom b) Rutherford atom c) nuclear d) liquid drop

75. Natural uranium consists of ----------- of U238

.

a) 0.28 % b) 0.72 % c) 99.28 % d) 9.28 %



Page – 4

76. Atom bombs were exploded over Nagasaki and Hiroshima in -------------.

a) India b) USA c) Russia d) Japan

77. Synchrocyclotron can accelerate particles to an energy of the order of ----------------.

a) 10 6 eV b) 10

3 eV c) 10

9 eV d) 10

8 eV

78. In PHWR , ---------------- oxide is used as fuel.

a) plutonium b) thorium c) silver d) uranium.

79. The energy value of the thermal neutrons is -------------- .

a) 1000 eV b) 10 MeV c) 200 MeV d) 0.025 eV

80. Cadmium or boron rods are called as ---------------- rods.

a) shielding b) reflector c) moderator d) control

81. A mixture of beryllium with plutonium is used as a source of ----------------.

a) protons b) electrons c) neutrons d) photons.

82. The boiling point of liquid sodium is --------------- .

a) 10 0C b) 100

0C c) 1000

0C d) 10000

0C

83. The name of the nuclear reactor in Kalpakkam is ------------- .

a) Yamini b) Kamini c) BARC d) Minmini

84. The total power generation by all the operating power rea ctors is ------------- .

a) 270 MW b) 27700 MW c) 2770 MW d) 20770 MW

85. The process of combining two or more number lighter nuclei to form a heavy nucleus is --------------- .

a) nuclear fission b) nuclear force c) nuclear fusion d) nuclear reaction

86. The principle involved in hydrogen bomb is --------------- .

a) nuclear fission b) nuclear force c) nuclear fusion d) nuclear reaction

87. The energy radiated per second by the sun is --------------- J

a) 3.8 X 10 28

b) 3.8 X 10 26

c) 3.8 X 10 22

d) 3.8 X 10 24

88. In sun , hydrogen and helium are in a state called --------------.

a) photosphere b) chromosphere c) thermosphere d) plasma

89. In proton – proton cycle fusion, the energy released is in the order of ------------ .

a) 36.7 MeV b) 26.7 MeV c) 16.7 MeV d) 46.7 MeV.

90. The study of cosmic rays started with ---------------

a) cyclotron b) GM counter c) gold leaf electroscope d) capacitor

91. The intensity of cosmic rays is -------------- at the equator.

a) maximum b) zero c) minimum d) infinity

92. The intensity of cosmic rays is maximum at the height of ------------ km.

a) 42 b) 90 c) 20 d) 30

93. In pair production, the particles produced are -----------------.

a) electron - proton b) electron - positron c) neutron - proton d) proton - positron

94. The name cosmic rays was given by --------------.

a) Marie Currie b) Millikan c) Rutherford d) Henri Becquerel

95. The energy of the primary cosmic rays is in the order of -------------------- .

a) 10 7 eV b) 10

8 MeV c) 10

9 meV d) 10

8 eV

96. The quantum of radiation with no charge and no mass is called ---------------.

a) electron b) photon c) proton d) neutron

97. The rest mass of ---------------- vary between 250 me and 1000 me .

a) electron b) photon c) proton d) mesons

98. The rest mass of the ---------------- vary from 2180 me to 3275 me.

a) hyperons b) photons c) protons d) mesons

99. 1 H 3 + 1 H

2 → 2 He

4 + -------------- + energy.

a) 1 H 1

b) o n 1

c) 1 H 2

d) 1 H 3

100. In GM counter, the potential difference of about -------------- is applied through a high resistance of ---------

a) 100 V, 100 MΩ b) 100 V, 1000 MΩ c) 1000 V, 100 MΩ d) 100 V, 10 MΩ

********* Best wishes *********


+2 Physics Unit : 9 SEMICONDUCTOR DEVICES AND THEIR APPLICATIONS MARKS: 100

1. Germanium and Silicon are most widely used as ……….

a) metals b) insulators c) semi conductors d) poor conductors

2. The resistivity of a semiconductor lie approximately between …….. Ωm at room temperature.

a) 10 -2 and 10 4 b) 10 -8 and 10 14 c) 10 -2 and 10 8 d) 10 11 and 10 16

3. A set of closely packed energy levels is called an ……….

a) valence level b) conduction level c) forbidden level d) energy band

4. Each silicon atom has ……. electrons.

a) 8 b) 6 c) 14 d) 4

5. The subshell 3p can accommodate a total of …….. electrons.

a) 6 b) 8 c) 4 d) 14

6. The electrons in the outermost level are called ……... electrons.

a) valence b) conduction c) non-conducting d) none of the above

7. The energy gap between the valence band and the conduction band is called ……..

a) valence level b) conduction level c) forbidden energy gap d) energy band

8. In insulators, the forbidden energy gap is more than ………

a) 1.1 eV b) 3 eV c) 0.7 eV d) 0 eV

9. In glass, the forbidden energy gap is in the order of ……… at 0 K.

a) 10 eV b) 3 eV c) 0.7 eV d) 0 eV

10. The resistivity of insulator approximately lies between ……….

a) 10 -2 and 10 4 b) 10 -8 and 10 14 c) 10 -2 and 10 8 d) 10 11 and 10 16

11. The forbidden energy gap is of the order of ………. for Germanium.

a) 0.7 eV b) 1.1 eV c) 10 eV d) 3 eV

12. The forbidden energy gap is of the order of ……… for Silicon.

a) 10 eV b) 3 eV c) 0.3 eV d) 1.1 eV

13. The conductivity of a semi conductor is of the order of ………… mho / m

a) 10 3 b) 10 2 c) 10 6 d) 10 9

14. The forbidden energy gap is of the order of ………. eV for conductors.

a) 0.7 b) 1.1 c) 10 d) zero

15. A semiconductor in the purest form is called …………

a) extrinsic b) intrinsic c) conductor d) insulator

16. In a pure Germanium semiconductor, the number of valence electrons is ………..

a) 8 b) 6 c) 4 d) 16

17. In intrinsic semiconductors, the electrons and the holes move in the ……….. directions.

a) same b) opposite c) parallel d) perpendicular

18. The process of addition of a very small amount of impurity into an intrinsic semiconductor is …..

a) diffusion b) doping c) diffraction d) deflection

19. When a small amount of impurity atoms are added to a pure semiconductor, it is …………. semiconductor.

a) intrinsic b) extrinsic c) poor d) non-conducting

20. The valency bismuth, antimony, phosphorus etc is ………

a) 3 b) 4 c) 5 d) 6

21. The valency of aluminium, gallium, boron etc is ………..

a) 3 b) 4 c) 5 d) 6

22. If arsenic is added to a pure germanium, the resulting crystal is called ……… semiconductor.

a) P –type b) N-type c) intrinsic d) R - type

23. If boron is added to a pure germanium, the resulting crystal is called ……….. semiconductor.

a) P-type b) N-type c) intrinsic d) R – type

24. In N-type semiconductor , ……….. are the majority charge carriers.

a) protons b) positrons c) holes d) electrons

25. In P-type semiconductor, ……… are the majority charge carriers.

a) protons b) positrons c) holes d) electrons

26. The region which does not have any mobile charges very close to the PN junction is called …………. region.

a) depletion b) forbidden c) break down d) none of the above

+ 2 Physics Unit : 9 …………. Continued in Page - 2


Page – 2

27. In a PN junction diode, the potential barrier is approximately ……… for a silicon PN junction.

a) 0.3 V b) 1.1 V c) 0.7 V d) 5 V

28. In a PN junction diode, the potential barrier is approximately …….. for a germanium PN junction.

a) 0.3 V b) 1.1 V c) 0.7 V d) 5 V

29. In a PN junction diode forward bias, the potential barrier ………….

a) increases b) does not decrease c) reduces d) is constant

30. In a PN junction diode reverse bias, the potential barrier is …………

a) increases b) does not decrease c) reduces d) is constant

31. In a PN junction diode forward bias, the current is of the order of ………..

a) nA b) pA c) m A d) µ A

32. In a PN junction diode reverse bias, the current is of the order of …………

a) nA b) pA c) m A d) µ A

33. The circuit symbol for a semiconductor diode is ………

a) b) c) d)

34. In a PN junction diode forward bias, V / I is …………

a) a constant b) not a constant c) not a variable d) infinity

35. The conversion of AC into DC is called ………..

a) rectification b) oscillation c) diffraction d) modulation

36. A circuit which rectifies half of the a.c wave is called ……….. rectifier.

a) full wave b) half –wave c) bridge d) Colpitt’s

37. The ratio of the d.c power output to the a.c power input is known as rectifier ………..

a) power factor b) power gain c) efficiency d) transformer ratio

38. The efficiency of a half wave rectifier is approximately …………

a) 25 % b) 50 % c) 40.6 % d) 81.2 %

39. The efficiency of a bridge rectifier is approximately ………..

a) 25 % b) 50 % c) 40.6 % d) 81.2 %

40. There are two mechanisms which give rise to the breakdown of a PN junction under reverse bias

condition. They are (i) Avalanche breakdown and (ii) ……….. breakdown.

a) diode b) transistor c) capacitor d) zener

41. The reverse biased heavily doped semiconductor PN junction diode, which is operated

in the breakdown region is called ………… diode.

a) Zener b) PN junction forward bias c) inductor d) none of the above

42. In a Zener diode, at a particular reverse bias voltage called ……., the current

increases enormously.

a) zener voltage b) critical voltage c) bias voltage d) internal barrier

43. A forward biased PN junction diode which emits visible light when energized is called ………

a) RED b) LEAD c) LED d) LCD

44. In instrument displays, calculators and digital watches ........... is used.

a) RED b) LEAD c) LED d) LCD

45. In a junction transistor, the thickness of the base layer is about ………… microns.

a) 10 b) 50 c) 25 d) 100

46. In a junction transistor, the ………. region is heavily doped.

a) base b) collector c) depletion d) emitter

47. In a junction transistor, the ………. region physically larger in size.

a) base b) collector c) depletion d) emitter

48. In a junction transistor, the emitter – base junction is ……… biased.

a) forward b) reverse c) inverse d) positve

49. In a junction transistor, the collector – base junction is ……….. biased.

a) forward b) reverse c) direct d) positve

50. In a CB mode transistor circuit, the current gain α = ……….

a) I B / I E b) I C / I B c) I C / I E d) I E / I C

+2 Physics Unit : 9 …………. Continued in Page -3


Page - 3

51. In CE mode transistor circuit, the current gain is given by β = …….

a) I B / I E b) I C / I B c) I C / I E d) I E / I C

52. The value of α lies between …….. and …… .

a) 95, 99 b) 0.95 , 0.99 c) 9.5, 9.9 d) 50, 300

53. Usually β lies between ……. and ……...

a) 95, 99 b) 0.95 , 0.99 c) 9.5, 9.9 d) 50, 300

54. The relation between α and β is β = ………..

a) α / ( 1 + α ) b) ( 1 - α ) / α c) ( 1 + α ) / α d) α / ( 1 - α )

55. In a transistor, the ratio between emitter-base potential and base current is called …………

a) current gain b) output impedance c) input impedance d) output admittance

56. In the output characteristics, the region below the curve for IB =0 is called ………. region.

a) cut-off b) let-off c) depletion d) critical

57. In a transistor, the ratio between emitter-collector potential and collector current is called ………….


58. In a transistor, the ratio between collector current and the base current is called ………….


59. A circuit capable of magnifying the amplitude of weak signals is called …………

a) amplifier b) transistor c) oscillator d) modulator

60. There is always a phase reversal of ……… between the input and the output voltages in CE amplifier.

a) 180 0 b) 30 0 c) 90 0 d) 60 0

61. β of a transistor is very ………. to temperature changes.

a) sensitive b) soluble c) positive d) negative

62. In an amplifier, the ratio of the output and the input voltages is called …………

a) current gain b) output impedance c) input impedance d) voltage gain

63. The frequency response curve gives the relation between ………….

a) frequency and the voltage b) current and the voltage

c) frequency and the current d) frequency and the phase

64. The frequency interval between lower cut off and upper cut off frequencies is called ………..

a) band width b) current width c) voltage width d) channel width

65. When a fraction of the output signal is combined with the input, ..……… is said to exist in an amplifier.

a) rectification b) feed back c) modulation d) demodulation

66. If the magnitude of the input signal is reduced by the feedback, the feedback is called ………..

a) negative feedback b) positive feedback c) direct feedback d) regenerative feedback

67. If the magnitude of the input signal is increased by the feedback, it is called ………….

a) negative feedback b) positive feedback c) indirect feedback d) degenerative feedback

68. The voltage gain of the amplifier with positive feedback is …………..

a) Af = A / ( 1 + βA ) b) Af = A / ( 1 - βA ) c) Af = ( 1 - βA ) / A d) Af = ( 1 + βA ) / A

69. The term Aβ is called ………. and β is called feedback ratio.

a) loop gain b) current gain c) voltage d) power gain

70. The circuit which converts energy from d.c source into a periodically varying output is called ………….

a) amplifier b) oscillator c) modulator d) transistor

71. In oscillators βA = …………….

a) 2 b) 1/ β c) 1 d) 1 / A

72. If an oscillator generates a ………….. wave, it is called non-sinusoidal oscillator.

a) circular b) elliptical c) triangular d) rectangular

73. In a tank circuit, the frequency of oscillation is given by f = ……….

a) 1 / 2 π ( C )½

b) 1 / 2 π ( L )½

c) 1 / 2 π ( L C )½

d) 1 / 2 ( L C )½

74. In Colpitt’s oscillator, the total phase shift between the input and output is …….

a) 180 0 b) 30 0 c) 90 0 d) 360 0

75. Diodes and transistors are called ………. elements.

a) active b) inactive c) passive d) massive

+2 Physics Unit : 9 …………. Continued in Page - 4


Page - 4

76. Resistors and capacitors are called ……… elements.

a) active b) inactive c) passive d) massive

77. Circuits which are used to process digital signals are called ………... circuits.

a) digital b) analog c) active d) passive

78. If the signal current is in the form of continuous, time varying current, the signal is called ……… signals.

a) digital b) analog c) active d) passive

79. The integrated circuits which process the analog signals are called …………... ICs.

a) linear b) non-linear c) active d) passive

80. The typical IC chip sizes from about 40 X 40 mils to about ………….

a) 100 X 300 mils b) 300 X 3 mils c) 300 X 300 mils d) 300 X 30 mils

81. The Boolean equation of a OR gate is y = ……….

a) A – B b) A + B c) A.B d) A / B

82. The Boolean equation of a AND gate is y = ……….

a) A – B b) A + B c) A.B d) A / B

83. The Boolean equation of a NOT gate is y = ……….

a) b) A + B c) A.B d) A / B

84. The Boolean equation of a Ex - OR gate is …………..

a) b) A + B c) A.B d) A / B

85. The Boolean equation of a NOR gate is …………..

a) b) A + B c) A.B d) A / B

86. The Boolean equation of a NAND gate is …………

a) b) c) A+B d) A.B

87. One of the universal gate is ………….

a) OR b) AND c) NOT d) NOR

88. First De Morgan’s theorem is …………..

a) b) c) d) A / B

89. Second De Morgan’s theorem is = ……………..

a) b) c) d) A / B

90. OP-AMP consists of ….. transistors, ………. resistors and …….. capacitor.

a) 1, 11 , 20 b) 20, 11 , 1 c) 20,1,11 d) 1,20,11

91. In an inverting amplifier, the output voltage Vout = ………

a) ( 1 + Rf / R in ) Vin b) ( Rf / R in ) Vin c) - ( Rf / R in ) Vin d) - ( Rf X R in ) / Vin

92. In a non- inverting amplifier, the output voltage Vout = ………..

a) ( 1 + Rf / R in ) Vin b) ( Rf / R in ) Vin c) - ( Rf / R in ) Vin d) - ( Rf X R in ) / Vin

93. In a summing amplifier, the output voltage Vout = …………

a) ( 1 + Rf / R in ) Vin b) ( Rf / R in ) Vin c) - ( Rf / R in ) Vin d) – ( V1 + V2 )

94. In a difference amplifier, the output voltage Vout = …………

a) ( v1 - v2 ) b) ( Rf / R in ) Vin c) - ( Rf / R in ) Vin d) – ( V1 + V2 )

95. The property of the ……………. being deflected by electric and magnetic fields is used in CRO.

a) X –rays b) microwaves c) EM waves d) cathode rays

96. If the emitter current is 1 mA, then the collector current is approximately equal to ……. mA.

a) 5 b) 10 c) 9.9 d) 1

97. The unit of the out impedance ………..

a) ampere b) kelvin c) ohm d) mho

98. The device which is used to measure the current, the voltage and resistance is used to measure ……

a) GM counter b) oscillator c) ammeter d) multimeter

99. Multimeter is also called as …….. meter.

a) MUL b) CVR c) AVO d) MVO

100. The gate which is called as an inverter gate is ……………..

a) AND b) NAND c) NOR d) NOT

B.ELANGOVAN. M.Sc., M.Ed., M.Ed., PACHAIYAPPA’S HR.SEC.SCHOOL, KANCHEEPURAM-631501


+2 Physics Unit :10 Communication Systems Marks - 60

1. For communication purposes, radio waves and ………. are used.

a) microwaves b) IR rays c) UV rays d) X-rays

2. High frequency waves follow …. ……. propagation.

a) ionospheric b) ground wave c) surface wave d) space wave

3. All medium wave signals received during the day time use …………. propagation.

a) ionospheric b) longitudinal wave c) surface wave d) space wave

4. The radio waves which travel along the surface of the earth are called ………

a) sky waves b) longitudinal waves c) surface waves d) space waves

5. Radio waves propagated through the troposphere of the earth are known as ……..

a) sky waves b) longitudinal waves c) surface waves d) space waves

6. The portion of the earth’s atmosphere which extends upto 15 km from the surface of the earth is called ………

a) troposphere b) stratosphere c) ionosphere d) thermosphere

7. Space wave propagation is particularly suitable for the waves having frequencies above …………

a) 30 MHz b) 15 MHz c) 90 Hz d) 20 MHz

8. The ionised region containing free electrons, positive and negative ions in the earth’s atmosphere is called ……….

a) troposphere b) stratosphere c) ionosphere d) thermosphere

9. Long distance radio communication is possible through the ……… propagation.

a) sky waves b) longitudinal waves c) surface waves d) stationary waves

10. The refractive indices of the various layers in the ionosphere vary with respect to ……… of the incident wave.

a) density b) phase c) frequency d) intensity

11. The audio frequency ranges from ………..

a) 20 Hz – 200 Hz b) 200 Hz – 20000 Hz c) 20 Hz – 2000 Hz d) 20 Hz – 20000 Hz

12. The process of changing amplitude or frequency or phase of the carrier wave ( RF wave ) in

accordance with the intensity of the signal wave (AF wave ) is called …………

a) demodulation b) diffraction c) interference d) modulation

13. The process of changing amplitude of the carrier wave in accordance with the intensity of the signal wave is ……….

a) amplitude modulation b) phase modulation c) frequency modulation d) none of the above

14. The ratio of the amplitude change of the carrier wave after modulation to the amplitude of the carrier wave before

modulation is called ………. factor.

a) power b) spring c) modulation d) Q

15. Signal amplitude / carrier amplitude is called as ………. factor.


16. The strength and the quality of the transmitted signal can be determined by the ………..


+2 Physics Unit -10 ……… continued in page number : 2


Page : 2

17. When the modulation factor is ……….., the transmitted signal will not be very strong.

a) greater than one b) less than one c) equal to one d)

18. When the modulation factor is greater than one, ……….. is produced in the transmitted signal.

a) distortion b) strong signal c) weak signal d) none of the above

19. For effective modulation, the degree of modulation should never exceed ………..

a) 200% b) 100% c) 20% d) 50%

20. In AM, the component having a frequency greater than that of the carrier wave is called as the….

a) Upper Side Band b) Bottom Side Band c) Lower Side Band d) Middle Side Band

21. In AM, the component having a frequency lesser than that of the carrier wave is called as the …..

a) Upper Side Band b) Top Side Band c) Lower Side Band d) Middle Side Band

22. The magnitude of both the upper and lower side bands is …… times the carrier amplitude Ec .

a) m b) m /4 c) 2m d) m /2

23. In an AM wave, the bandwidth is from ( ωc - ωs ) to ( ωc + ωs ) i.e. …………. the signal frequency.

a) twice b) three times c) equal to d) half of the

24. The channel width = ……….. X maximum frequency of the modulating signal.

a) 3 b) 4 c) 6 d) 2

25. In an AM wave, the reception is generally ………

a) clear b) noiseless c) noisy d) strong

26. The efficiency of AM wave is ……….

a) high b) low c) medium d) strong

27. The messages cannot be transmitted over long distances in ………….

a) AM wave b) FM wave c) Phase modulated d) none of the above

28. The process of changing frequency of the carrier wave in accordance with the intensity of the signal wave is ……….


29. The frequency of the FM transmitter without signal input is called ……… frequency.

a) centre b) upper c) lower d) threshold

30. Carrier swing in FM transmitter = ………… X frequency deviation.

a) 3 b) 4 c) 6 d) 2

31. FM receiver gives ………. reception.

a) weak b) noiseless c) noisy d) no

32. The process of changing phase of the carrier wave in accordance with the intensity of the signal wave is ………..


33. The phase modulation generally uses a …….. bandwidth than FM.

a) smaller b) larger c) higher d) none of the above

+2 Physics Unit -10 ……… continued in page number : 3


Page : 3

34. The centre frequency is extremely stable in ……….


35. Frequency modulated systems are operated usually at a frequency above ……….

a) 40 MHz b) 20 KHz c) 40 KHz d) 20 MHz

36. In a superheterodyne receiver, the output from the mixer will have a frequency of ………. .

a) 555 MHz b) 455 kHz c) 1000 Mhz d) 455 MHz

37. In television, usually sound signals are ……. … modulated and picture signals are amplitude modulated.

a) frequency b) phase c) amplitude d) both frequency and phase

38. A television camera converts the light energy into …………

a) electrical energy b) heat energy c) sound energy d) chemical energy

39. A blanking pulse is a high negative potential applied to the ………. of the electron gun.

a) control grid b) anode c) cathode d) filament

40. In a 625 line system, transmitting 25 frames per second, the horizontal scanning frequency is …………. Hz.

a) 15,625 b) 14,625 c) 12,625 d) 10,625

41. In a 625 line system, transmitting 25 frames per second, time taken to scan one line is ……

a) 164 μ s b) 64 μ s c) 44 μ s d) 264 μ s

42. Video signals upto about ………. are allowed in CCIR mode.

a) 25 MHz b) 15 MHz c) 10 MHz d) 5 MHz

43. The system which uses radio waves to detect and to fix the position of targets at a distance is called as……….

a) RADAR b) SONAR c) LASER d) MASER

44. Air and sea navigation is made entirely safe with ………. installations.


45. The name ……… is the abbreviation of the term Modulator and Demodulator.

a) FAX b) RADAR c) MODEM d) MASER

46. The device that is used to convert digital signals into analog signals capable of being transmitted

over telephone lines is called as ………….


47. The electronic system for transmitting graphical information by wire or radio is called as ………


48. Coherent light can be detected by ………

a) photo – diodes b) PN junction diodes c) zener diodes d) transistors

49. The principle of ……. is used for the transmission of light signals through an optical fiber.

a) reflection b) total internal reflection c) refraction d) diffraction

50. Satellite orbiting the earth will be geostationary when it is about …….. km away from the earth.

a) 16,000 b) 26,000 c) 36,000 d) 46,000

+2 Physics Unit -10 ……… continued in page number :4


Page : 4

51. The downlink frequencies are kept different from the uplink frequencies in order to avoid ………

a) reflection b) interference c) refraction d) diffraction

52. In satellite communication the downlink frequencies are kept different from the uplink frequencies by ………..

a) 2 kHz b) 2 MHz c) 2 GHz d) 20 kHz

53. The ……… amplifier isolates the RF power amplifier from the oscillator. This arrangement keeps

the frequency of the crystal controlled oscillator as a constant.

a) power b) voltage c) buffer d) AF

54. For FM receivers, the IF is ………..

a) 10.7 MHz b) 20.7 MHz c) 30.7 MHz d) 40.7 MHz

55. The transmitter and receiver switch in a ………….. is called as a duplexer.


56. In ………. modulation, both the phase and the frequency of the carrier wave varies.

a) frequency b) phase c) amplitude d) none of the above

57. The printed documents to be transmitted by fax are converted into electrical signals by the process ………

a) scanning b) modulation c) demodulation d) interference

58. The purpose of dividing each frame into two fields so as to transmit 50 views of the picture per second is to avoid ………

a) flicker in the picture b) to remove the noise c) easy to handle the HF waves d) modulation

59. Digital signals are converted into analog signals using ……………

a) FAX b) MODEM c) cable d) co-axial cable

60. The RF channel in a radio transmitter produces ……………

a) audio signals b) high frequency carrier waves

c) low frequency carrier waves d) both audio and high frequency carrier waves.

***** BEST WISHES *****

From

B.ELANGOVAN. M.Sc., M.Ed., M.Ed., PACHAIYAPPA’S HR.SEC.SCHOOL,

KANCHEEPURAM-631501

( Dr Radhakrishnan State level Best Teacher Award Recipient - 2011)

e-mail id : [email protected]

Phone number : 9444438464



+2 Physics

Unit – 6 Atomic Physics

1. What are the conditions to achieve the laser action? ( M – 06, J – 07, O - 13, J - 14 )

Conditions to achieve laser action

(i) There must be an inverted population i.e. more atoms in the excited state than in

the ground state.

(ii) The excited state must be a metastable state.

(iii) The emitted photons must stimulate further emission. This is achieved by the use of the

reflecting mirrors at the ends of the system.

2. An X-ray diffraction of a crystal gave a closest line at an angle of 6o27’. If the wavelength of

X-ray is 0.58Ao, find the distance between the two cleavage planes. ( M – 06, O - 13, O - 14, O - 15 )

2d Sinθ = nλ

Here, n = 1.

d = λ / 2 Sinθ

d = 0.58 / 2 X Sin 6o27’

d = 0.58 / 2 X 0.1123

Hence, distance between the two cleavage planes d = 2.582 A0

3. What is the principle of Millikan’s oil drop method? ( J – 06, M – 12, J - 15 )

Principle

This method is based on the study of the motion of uncharged oil drop under free fall due to

gravity and charged oil drop in a uniform electric field.

By adjusting uniform electric field suitably, a charged oil drop can be made to move up or

down or even kept balanced in the field of view for sufficiently long time and a series of observations

can be made.

4. Calculate the longest wavelength that can be analysed by a rock salt crystal of spacing d = 2.82 Ao

in the first order. ( J – 06, O – 08, M – 09, J - 10, O – 10, M - 11, J – 12 )

Data : d = 2.82 Å = 2.82 × 10−10

m ; n = 1 ; λmax = ?

Solution : For longest wavelength, (sin θ) max = 1

∴ 2d (sin θ)max = λmax

(or) λmax = 2 ×2.82 × 10−10

×1 / 1

λmax = 5.64 × 10−10

m


5. What are the characteristics of laser beam? ( O – 06, J – 09, M – 10 , J – 10, J – 12, O - 12 )

Characteristics of laser

The laser beam (i) is monochromatic. (ii) is coherent, with the waves, all exactly in phase with

one another, (iii) does not diverge at all and (iv) is extremely intense.

6. The Rydberg’s constant for hydrogen is 1.097 X 107 ms

-1. Calculate the shortest wavelength limit of

Lyman series. ( O – 06, O – 09 ) and longest wavelength ( M - 15) (O – 06, O – 09, M - 15 )

Data : R = 1.097 × 107 m

−1

For short wavelength limit of Lyman Series,

n1 = 1, n2 = ∞, λs = ?

Solution: The wave number for Lyman series is,

For short wavelength limit,

7. State Moseley’s law. ( M – 07, M – 08, M – 09, M - 11, J - 14 )

The frequency of the spectral line in the characteristic X-ray spectrum is directly

proportional to the square of the atomic number (Z) of the element considered.

i.e ν α Z2 or ν = a(Z − b)

where a and b are constants depending upon the particular spectral line.

8. Define: ionisation potential. ( M – 07, O - 10 )

The ionisation potential is that accelerating potential which makes the impinging

electron acquire sufficient energy to knock out an electron from the atom and thereby ionise the atom.

13.6 V is the ionisation potential of hydrogen atom.

9. What is ionisation potential energy? ( J – 09 )

For hydrogen atom, the energy required to remove an electron from first orbit to

its outermost orbit(n=∞) is 13.6-0 = 13.6eV. This energy is known as the ionization potential energy

for hydrogen atom.


10. How much should be the voltage of an X-ray tube so that the electrons emitted from the cathode may

give an X-ray of wavelength 1 Ao after striking the target? ( J – 07, M - 13 )

λmin = 12400 A0

/ V

Hence, V = 12400 A0

/ λmin

= 12400 A0

/ 1 Ao = 12400 volt

11. What is hologram? ( O – 07 )

Holography When an object is photographed by a camera, a two dimensional image of three dimensional

object is obtained. A three dimensional image of an object can be formed by holography.

In ordinary photography, the amplitude of the light wave is recorded on the

photographic film. In holography, both the phase and amplitude of the light waves are recorded on the

film. The resulting photograph is called hologram.

12. Write down two important facts of Laue experiment on X-ray diffraction. ( O – 07, J – 08 )

The Laue experiment has established following two important facts :

(i) X–rays are electro magnetic waves of extremely short wave length.

(ii) The atoms in a crystal are arranged in a regular three dimensional lattice.

13. Write any three medical applications of laser. ( M – 08,O – 09,J – 11,O – 11 )

Medical applications (i) In medicine, micro surgery has become possible due to narrow angular spread of the laser beam.

(ii) It can be used in the treatment of kidney stone, tumour, in cutting and sealing the small blood

vessels in brain surgery and retina detachment.

(iii) The laser beams are used in endoscopy.

(iv) It can also be used for the treatment of human and animal cancer.

14. Write any three applications of laser in industry. ( J – 08 )

Industrial applications

(i) The laser beam is used to drill extremely fine holes in diamonds, hard sheets etc.,

(ii) They are also used for cutting thick sheets of hard metals and welding.

(iii) The laser beam is used to vapourize the unwanted material during the

manufacture of electronic circuit on semiconductor chips.

(iv) They can be used to test the quality of the materials.

15. Explain any one of the drawbacks of Rutherford atom model. ( O – 08 )

According to classical electromagnetic theory, the accelerating electron must radiate energy at

a frequency proportional to the angular velocity of the electron. Therefore, as the electron spiral towards

the nucleus, the angular velocity tends to become infinity and hence the frequency of the emitted energy

will tend to infinity. This will result in a continuous spectrum with all possible wavelengths.


16. Find the minimum wavelength of X-rays produced by an X-ray tube operating at 1000 kV. (M-10,J-13 )

λmin = 12400 A0

/ V

Hence, λmin = 12400 X 10-10

/ 10 6

= 0.0124 A0

17. The minimum wavelength of X-rays produced in a Coolidge tube is 0.05 nm. Find the operating

voltage of the Coolidge tube. ( J – 11 )

λmin = 12400 A0

/ V = 0.5 X 10 -10

m

Hence, V = 12400 A0

/ λmin

= 12400 A0

/(1/2)Ao = 24800 volt

18. What is excitation potential energy of an atom? ( M - 15 )

The energy required to raise an atom from its normal state into an excited state is called

excitation potential energy of the atom.

For example, the energy required to transfer the electron in hydrogen atom from the ground

state to the first excited state = (13.6-3.4) = 10.2eV.

19. What is fine structure of spectral lines?

When the spectral line of hydrogen atom is examined by spectrometers having high resolving

power, it is found that a single line is composed of two or more close components. This is known as

the fine structure of spectral lines. Bohr’s theory could not explain the fine structure of spectral lines.

20. What are Stark and Zeeman effects?

It is found that when electric or magnetic field is applied to the atom, each of the spectral line

split into several lines. The former effect is called as Stark effect, while the latter is known as Zeeman

effect.

21. Give the differences between hard X-rays and soft X-rays. ( M - 14 )


22. Give the drawbacks of Sommerfeld’s atom model. ( O – 11 )

Drawbacks of Sommerfeld’s atom model:

(i) It could not explain the distribution and arrangement of electrons in atoms.

(ii) Sommerfeld’s model was unable to explain the spectra of alkali metals such as sodium, potassium

(iii) It could not explain Zeeman and Stark effect.

(iv) This model does not give any explanation for the intensities of the spectral lines.

23. Give the applications of Moseley’s law. ( O - 12, J - 13, O - 14, J - 15 )

(i) The elements are arranged in the periodic table according to the atomic numbers and not

according to the atomic weights.

(ii) led to the discovery of new elements like hafnium (72), technetium (43), rhenium (75) etc.

(iii) helpful in determining the atomic number of rare earths, thereby fixing their position in the

periodic table.

24. What are the two important facts established by Laue experiment ? ( M – 13 )

1. X- rays are electromagnetic waves of extremely shot wavelength.

2. The atoms in a crystal are arranged in a regular three dimensional lattice.

25. A beam of electrons moving with a speed of 4 X 107 ms

-1 is projected normal to a magnetic field of B

= 10-3

Wb m-2. What is the path of the beam in the magnetic field? ( M – 12 )

Solution : Since, the electrons are released normally to the magnetic field,

the electrons travel in a circular path.

∴ Bev = mv2 / r

r = mv / Be = 9.11 X 10-31

X 4 X 107 / 10

-3 X 1.6 X 10

-19

Radius of the path r = 0.2275 m.

26. A beam of electrons passes through a transverse magnetic field of B = 2 X 10-3

tesla and an electric

field E = 3.4 X 104

V/m. If the path of the electron beam is undeviated , calculate the speed of

the electrons ( M - 14 )

Velocity of the electron beam v = E / B

∴ v = 3.4 X 104

/ 2 X 10-3

v = 1.7 X 107

m/s

27. Write any three properties of cathode rays. ( O - 15 )

1) They travel in straight lines.

2) They possess momentum and kinetic energy.

3) They ionize the gases.

4) They affect the photographic plates.



+ 2 Physics Unit : 7 Dual nature of radiation , Matter and Relativity

1. What is photoelectric effect?

Photoelectric emission is the phenomena by which a good number of

substances, chiefly metals, emit electrons under the influence of radiation

such as γ rays, X-rays, ultraviolet and even visible light.

2. What is cut-off or stopping potential? ( O – 09, O - 12 )

The minimum negative (retarding) potential given to the anode for which

the photo electric current becomes zero is called the cut-off or stopping potential.

3. Define : threshold frequency. ( J - 13 )

The minimum frequency of incident radiation below which the photoelectric emission is not

possible completely, however high the intensity

of incident radiation may be.

The threshold frequency is different for different metals.

4. What is dual character of light?

Light behaves as particles of energy in the higher energy region and as waves

in the lower energy region.

5. Name the types of photoelectric cells.

The photo electric cells are of three types:

(i) Photo emissive cell

(ii) Photo voltaic cell and

(iii) Photo conductive cell.

6. Give three applications of photoelectric cells. ( J – 06, M – 10,O – 10, J – 12 )

(i) Photoelectric cells are used for reproducing sound in cinematography.

(ii) They are used for controlling the temperature of furnaces.

(iii) Photoelectric cells are used for automatic switching on and off the street lights.

(iv) Photoelectric cells are used in the study of temperature and spectra of stars.

(v) Photoelectric cells are used in burglar alarm and fire alarm.

(vi) These cells are used in instruments measuring light illumination.

(vii) These cells are used in opening and closing of door automatically.

7. What are de Broglie waves?

Matter in motion must be accompanied by waves called de Broglie waves.

de Broglie wavelength λ = h / mv

8. An electron beam is accelerated through a potential difference of 104

volt. Find the de Broglie

wavelength.

λ = 12.27 A o / √V

λ = 12.27 A o / √10

4

= 0.1227 A o


9. What are the uses of an electron microscope? ( M – 07, O - 15 )

Uses of electron microscope :

(i) It is used in the industry, to study the structure of textile fibres, surface of

metals, composition of paints etc.

(ii) In medicine and biology, it is used to study virus, and bacteria.

(iii) In Physics, it has been used in the investigation of atomic structure and

structure of crystals in detail.

10. Why X-rays are not used in microscopes?

1) the wavelength of X-rays is smaller than that of the visible light.

2) X-rays cannot be focussed as visible radiations are focussed using lenses.

3) X-rays can not be deflected by electric and magnetic fields.

11. What are the limitations of electron microscope? ( M – 06, M – 09, M – 12 )

An electron microscope is operated only in high vacuum.

This prohibits the use of the microscope to study living organisms which

would evaporate and disintegrate under such conditions.

12. What is a frame of reference?

A system of co-ordinate axes which defines the position of a particle in two or three

dimensional space is called a frame of reference.

13. What are inertial and non-inertial frame of references? ( O – 06, M – 08, O – 11 )

(i) Inertial (or) unaccelerated frames:

Bodies in this frame obey Newton’s law of intertia and other laws of Newtonian mechanics.

In this frame, a body remains at rest or in continuous motion unless acted upon by an external

force.

(ii) Non-inertial (or) accelerated frames:

A frame of reference is said to be a non-intertial frame, when a body not acted upon by

an external force, is accelerated. In this frame, Newton’s laws are not valid.

14. State the fundamental postulates of special theory of relativity? ( O – 07, J – 09,M – 11, J - 13 )

The two fundamental postulates of the special theory of relativity are :

(i) The laws of Physics are the same in all inertial frames of reference.

(ii) The velocity of light in free space is a constant in all the frames of reference.

15. According to classical mechanics, what is the concept of time ? ( J – 10 )

According to classical mechanics,

(i) The time interval between two events has the same value for all observers irrespective

of their motion.

(ii) If two events are simultaneous for an observer, they are simultaneous for all observers,

irrespective of their position or motion.


16. The kinetic energy of an electron 120 eV. Calculate the de Broglie wavelength of electron. ( J – 07, J – 08)

λ = h / √2mE

λ = 6.626 X 10-34

/ √ 2 X 9.1 X 10 -31

X 120 X 1.6 X 10-19

λ = 1.121 X 10 -10

m

17. The work function of a metal surface is 6.626 X 10-19

joule. Calculate the frequency of the radiation?

Work function W = hγo

The frequency of the radiation γo = W / h

= 6.626 X 10 -19

/ 6.626 X 10 -34

= 1015

Hz.

18. Find the de Broglie wavelength of electron in the fourth orbit of hydrogen atom. ( J – 11 )

We know that, λ = 2πr / n

λ4 = 2πr 4 / 4

= 2π( 4 2 r1 ) / 4

= 2 X 3.14 X 4 X 0.53 A0

= 13.313 A

0

19. The work function of a metal surface is 1.8 eV. Calculate the threshold wavelength. ( O – 08 )

Work function W = hγo = h C / λ 0

λ 0 = h C / W

= 6.626 X 10-34

X 3 X 10

8 / 1.8 X 1.6 X 10

-19

= (19.878 / 2.88) X 10-7

m

= 6.902 X 10-7

m

***** Best of luck *****


+2 Physics UNIT – 8 Nuclear Physics Three marks Q & A

1. Select the pairs of isotopes, isobars and isotones from the following nuclei:

11 Na 22

, 12 Mg 24

, 11 Na 24

, 10 Ne 23

( M – 12 )

Isotopes are 11 Na 22

, 11 Na 24

Isobars are 12 Mg

24, 11 Na

24

Isotones are

11 Na

24, 10 Ne

23

2. In 17 Cl 35

, calculate the number of protons, neutrons and electrons.

Number of protons = 17, Number of electrons = 17, Number of neutrons = 18

3. Tritium has a half life period of 12.5 years. What fraction of the sample will be left over

after 25 years? ( M - 10, J – 12, O - 12 )

HLP = 12.5 years

Number of HLPs in 25 years = 25 / 12.5 =2

Fraction of the sample left over after 25 years = (½) 2

= ¼

4. State the radioactive law of disintegration. ( O – 13 )

The rate of disintegration at any instant is directly proportional to the number

of radioactive atoms of the element present at that instant.

5. Define: mass defect. ( O -10 )

The difference in the total mass of the nucleons and the actual mass of the nucleus is

known as the mass defect.

6. Define: binding energy. ( O – 09 )

The energy equivalent of mass defect is called as binding energy.

∴ Binding energy = [ZmP + Nmn – m] c2

= Δm c2

. Here, Δm is the mass defect.

7. Write any three findings of binding energy curve. ( O – 06 )

(i) The binding energy per nucleon reaches a maximum of 8.8 MeV at A = 56,

corresponding to the iron nucleus (26Fe56). Hence, iron nucleus is the most stable.

(ii) The average binding energy per nucleon is about 8.5 MeV for nuclei having mass

number

ranging between 40 and 120. These elements are comparatively more stable and non

radioactive.

(iii) For higher mass numbers the curve drops slowly and the BE/A is about 7.6 MeV for

uranium. Hence, they are unstable and radioactive.

8. What are the uses of nuclear reactor? ( J - 11, M - 13 )

Nuclear reactors are used for

i) power production

ii) producing radio-isotopes

iii) scientific research


9. State any three properties of the nuclear forces. ( J – 08 )

(i) Nuclear force is charge independent.

(ii) Nuclear force is the strongest known force in nature.

(iii) Nuclear force is not a gravitational force.

(iv) Nuclear force is a short range force.

10. What is artificial radioactivity? ( J – 12, O - 12 )

The phenomenon by which even light elements are made

radioactive by artificial or induced methods is called artificial radioactivity.

11. What is α - decay? Give an example. ( M – 06, M - 13 )

α-decay

When a radioactive nucleus disintegrates by emitting an α-particle,

the atomic number decreases by two and mass number decreases by four.

Example : Radium (88Ra226

) is converted to radon (86Rn222

) due to α−decay

88Ra226

→ 86Rn222

+ 2He4

12. Define: roentgen. ( J – 07, O – 08 )

One roentgen ( 1R ) is defined as the quantity of radiation which produces 1.6 × 1012

pairs of

ions in 1 gram of air.

13. Define: activity and Curie ( O – 06, M – 08, M-10, O - 10, J - 13 )

The activity of a radioactive substance is defined as the rate at which the atoms decay.

Curie is defined as the quantity of a radioactive substance which gives 3.7 × 1010

disintegrations per second or 3.7 × 10

10 becquerel.

14. State any three properties of the neutrons. ( J – 06, M – 08, M – 09, J – 11, O - 11, M - 14 )

(i) Neutrons are the constituent particles of all nuclei, except hydrogen.

(ii) As they are neutral particles,they are not deflected by electric and magnetic fields.

(iii) As neutrons are neutral, they can easily penetrate any nucleus.

(iv) Neutrons are stable inside the nucleus. But outside the nucleus they are unstable.

15. How do you classify the neutrons in terms of its kinetic energy? ( J – 09 )

Neutrons are classified according to their kinetic energy as

(a) slow neutrons and (b) fast neutrons.

Neutrons with energies from 0 to 1000 eV are called slow neutrons.

Neutrons with energies in the range between 0.5 MeV and 10 MeV are called fast neutrons.

16. Define: critical mass and critical volume. ( O – 08, O – 15 )

The minimum size in which atleast one neutron is available for further fission reaction.

The mass of the fissile material at the critical size is called critical mass.

The chain reaction is not possible if the size is less than the critical size.


17. What is a breeder reactor? ( M – 09 , J - 15 )

92U238

and 90Th232

are not fissile materials but are abundant in nature. In the reactor,

these can be converted into a fissile material 94Pu239

and 92U233

respectively by absorption of

neutrons.

The process of producing more fissile material in a reactor in this manner than

consumed during the operation of the reactor is called breeding. A fast reactor can be designed

to serve as a good breeder reactor.

18. What is the use of control rods? Mention any two control rods. ( O – 07 )

The control rods are used to control the chain reaction. They are very good absorbers of

neutrons. The commonly used control rods are made up of elements like boron or cadmium. In

our country, boron carbide (B4C) is used as control rod.

19. Write short notes on proton – proton fusion in sun. ( M -11 )

Proton – Proton cycle

1H1 + 1H

1 → 1H

2 + 1e

0 + ν (emission of positron and neutrino)

1H1 + 1H

2 → 2He

3 + γ (emission of gamma rays)

2 2He3

→ 2He4

+ 2 1H1

The reaction cycle is written as

4 1H1 → 2He

4 + 2 1e

0 + 2ν + energy (26.7 MeV)

Thus four protons fuse together to form an alpha particle and two Positrons with a

release of large amount of energy.

20. What are cosmic rays? ( J – 08, J - 10, O - 14 )

The ionising radiation many times stronger than γ-rays entering the earth from all the

directions from cosmic or interstellar space is known as cosmic rays. The name, cosmic rays

was given by Millikan. The cosmic rays can be broadly classified into primary and secondary

cosmic rays.

21. What percentage of a given radioactive substance will be left after 5 half -life periods? ( M -11 )

The remaining part of radioactive substance = ( ½ ) 5

Hence, The percentage of remaining part of

radioactive substance = ( ½ ) 5

X 100%

= 3.125 %

22. What is pair production and pair annihilation? ( M – 06, J – 06, M - 07, M - 14 )

Pair production:

The conversion of a photon into an electron−positron pair on its interaction with the

strong electric field surrounding a nucleus is called pair production.

Pair annihilation :

The converse of pair production in which an electron and positron combine to produce

a photon is known as annihilation of matter.


23. The half life of radon is 3.8 days. Calculate mean life. ( M – 07, O – 09, J – 09 )

Half Life Period HLP T½ = 0.6931 / λ = 0.6931 τ

Hence, Mean life τ = T½ / 0.6931 = 3.8 / 0.6931

= 5.483 days.

24. What are leptons? Give examples. ( J – 07, M – 12, O - 15 )

Leptons:

Leptons are lighter particles having mass equal to or less than about 207 times the mass

of an electron except neutrino and antineutrino.

This group contains particles such as electron, positron, neutrino, antineutrino, positive

and negative muons. The electron and positron are the antiparticles.

Neutrino and antineutrino are also associated with β-ray emission. The neutrinos and

antineutrinos are massless and chargeless particles, but carrier of energy and spin. Muons were

discovered in cosmic ray studies.

25. The half life period of 84Po218

is 3 minutes. What percentage of the sample has decayed in 15 minutes?

( O - 07, J - 13, O - 14, J - 15 )

1 HLP = 3 minutes

In 15 minutes, there are 3 HLPs

The remaining part of radioactive substance = ( ½ ) 3

Hence, The percentage of remaining part of

radioactive substance = ( ½ ) 3

X 100%

= 12.5 %

Decayed percentage = 100 – 12.5 = 87.5 %

26. The radioactive isotope 84Po214

undergoes a successive disintegration of two α decays and two β

decays. Find the atomic number and the mass number of the resulting isotope. ( J – 09, O - 14 )

For two α decays:

84Pa214

→ 82 A 210

→ 80 B 206

For two β decays :

80 B 206

→ 81 C 206

→ 82 D 206

The resulting isotope is lead with mass number 206 and atomic number 82. ( Pb )

27. What are the methods of producing radio-isotopes ? ( J - 14 )

1. By placing the target element in a nuclear reactor, where plenty of neutrons are available

2. To bombard the target element with particles from particle accelerators like cyclotron.

28. 92U238

undergoes a successive disintegration of three α decays and two β decays.

Find the resulting isotope. ( J – 14 )

For two α decays: 92U238

→ 90 A 234

→ 88 B 230

→ 86 C 226

For two β decays : 86 C 226

→ 87 C 226

→ 88 D 226

The resulting isotope is 88 Ra 226


+2 Physics UNIT - 9 Semiconductor devices and their Applications

1. What is an intrinsic semiconductor? Give any two examples. ( M – 06, O - 15 )

i) A semiconductor which is pure and contains no impurity is known as an intrinsic semiconductor.

ii) In an intrinsic semiconductor, the number of free electrons and holes are equal.

Common examples of intrinsic semiconductors are pure germanium and silicon.

2. The gain of an amplifier without feedback is 100 and the gain of an amplifier with

feedback is 200.Calculate the feedback fraction. ( M – 06 )

Solution : Voltage gain after feedback,

Af = A / 1 – Aβ

200 = 100 / 1 - 100 β

2 = 1 / 1 - 100 β

2 – 200 β = 1 (i.e) 200 β = 1

β = 1 /200 = 0.005

3. Draw the circuit diagram for NPN transistor in common emitter ( CE ) mode. ( M – 06, O – 06 )

C – collector E – emitter B – base

4. Mention any three advantages of integrated circuit. ( M – 06, O – 06, J -10, J – 11,M – 14 )

i) Extremely small in size ii) Low power consumption iii) Reliability

iv) Reduced cost v) very small weight vi) easy replacement

5. Define input impedance of a transistor in CE mode. ( J – 06, J – 11 )

Input impedance:

It is the ratio of small change in base-emitter voltage to the corresponding change in

base current at a given VCE.

Input impedance ri = ( ΔVBE / ΔIB ) VCE

6. Define output impedance of a transistor. ( O – 08, O – 09 )

Output impedance:

It is the ratio of small change in collector-emitter voltage to the corresponding

change in collector current at a given constant IB.

Output impedance ro = ( ΔVCE / ΔIC ) IB


7. When the negative feedback is applied to an amplifier of gain 50, the gain falls to 25.

Calculate the feedback ratio. ( J – 06, O – 09, M-10, O - 10, J - 14 )

Af = A / 1 + Aβ

25 = 50 / 1 + 50 β

1 = 2 / 1 + 50 β

1 + 50 β = 2 (i.e) 50 β = 1

β = 1 /50 = 0.02

8. Draw circuit diagram for OR gate using diodes. ( J – 06 )

9. What is an extrinsic semiconductor? ( J – 06, J – 08, O - 10, M - 11, O -13, J - 14 )

An extrinsic semiconductor is one in which an impurity with a valency higher or lower than the

valency of the pure semiconductor is added, so as increase the electrical conductivity of the

semiconductor.

10. What is Zener breakdown? ( O – 06, J – 07, M – 08, M - 12, J - 12, J - 13 )

Zener diode is a reverse biased, heavily doped semiconductor (silicon or germanium) PN

junction diode, which is operated exclusively in the breakdown region.

When a small reverse bias is applied to the PN junction a very strong electric field is produced

across the thin depletion layer. This field breaks the covalent bonds. The reverse saturation current

increases enormously. This is Zener breakdown

11. The voltage gain of an amplifier without feedback is 100. If negative feedback is applied with

feedback fraction 0.1, calculate the voltage gain with feedback. ( O – 06, O - 11 )

A F = A / 1 + A β

= 100 / 1 + 100 X 1/10

= 100 / 11 = 9.09

12. What are advantages of negative network? ( J – 07, J – 08, O – 07, M - 11,M - 12, M - 13, J - 15 )

Advantages of negative network:

i) Highly stabilized gain

ii) Reduction in the noise level

iii) Increased bandwidth.

iv) Increased input impedance and decreased output impedance

v) Less distortion


13. Draw circuit diagram for AND gate using diodes and resistors. ( J – 07, M - 15 )

14. What is rectification? ( M – 07, M - 09, O - 14 )

The process in which alternating voltage or alternating current is converted into direct voltage

or direct current is known as rectification. The device used for this process is called as rectifier.

15. What is light emitting diode? Give any one of its uses. ( M – 07, J - 15, O - 15 )

A light emitting diode (LED) is a forward biased PN junction diode, which emits visible light

when energized.

LEDs are used for instrumental displays, calculators and digital watches.

16. When there is no feedback, the gain of the amplifier is 100. If 5% of the output voltage is

fed back into the input through a negative network, find the voltage gain after feedback. ( M – 07 )

A F = A / 1 + A β

= 100 / 1 + 100 X 5/100 = 100 / 6

= 16.66

17. Collector current Ic=25mA and base current Ib = 50µA.Find current gain β of a transistor

( J – 10, O - 12, M - 13 )

β = I C / I B

= 25X 10-3

/ 50 X 10-6

= 500

α = β / ( 1 + β ) = 500/501

= 0.998

18. Calculate the output of the given amplifier. ( J – 07 )

For first OP-AMP, For second OP-AMP,

Av = - Rf / Rin = -100/50 = - 2 Vout 2 = V1 - Vout = 5 – ( -2 )

Av = Vout / Vin = -2 = 7 volt

Hence, Vout = -2 X Vin = - 2V


19. Draw the circuit diagram for NPN transistor in common collector ( CC ) mode. ( M – 08 )

C – collector E – emitter B – base

20. State de Morgan’s theorem. ( M – 08, M – 09, J-10, M - 12, M - 13, M -15 )

First Theorem:

The complement of a sum is equal to the product of the complements.

Second Theorem:

The complement of a product is equal to the sum of the complements.

21. A transistor is connected in CE configuration. The voltage drop across the load resistance

( Rc) 3 k is 6 V. Find the base current. The current gain α of the transistor is 0.97. ( M – 08 )

The voltage drop across the load resistance = ICRC = 6V

IC = 6 / RC = 6 / 3 X 103 = 2 mA.

β = α / 1−α = 0.97 / 1 -0.97 = 32.33

I B = I C / β = 2 X 10 -3 / 32.33

= 61.86 μA

22. What is an integrated circuit? ( J – 08, J – 09, O - 12, O - 14 )

An integrated circuit consists of single-crystal chip of silicon containing both active ( diodes

and transistors ) and passive elements ( resistors and capacitors ) and their interconnections.

23. What is meant by doping? ( O – 08 )

The process of addition of very small amount of impurity into an intrinsic semiconductor

is called doping.


24. What the Barkhausen conditions for oscillations? ( O – 07, O – 08, J – 09, M - 10, O - 15 )

Barkhausen conditions:

(i) The loop gain Aβ=1 and

(ii) the net phase shift round the loop is 0 or integral multiples of 2π.

25. Name the different methods of doping in a semiconductor. ( O – 09, J - 13, M - 15 )

i) The impurity atoms are added to the semiconductors in its molten state.

ii) The pure semiconductor is bombarded by ions of impurity atoms.

iii) When the semiconductor crystal containing the impurity atoms in heated,

the impurity atoms diffuse into the hot crystal.

26. Give the important parameters of an operational amplifier. ( O – 07, M - 14 )

Important parameters of an operational amplifier:

(i) Very high input impedance or even infinity.

(ii) Very high gain.

(iii) Very low output impedance or even zero.

27. Draw the circuit diagram of inverting amplifier using operational amplifier. ( M – 11 )

28. Find the output of the following ideal operational amplifier. ( J – 08, M - 12, M - 15 )


29. Find the output of the following logic circuit. ( O – 08 )

30. Draw the circuit for summing amplifier. ( M – 09, M - 13, J - 13 )

31. Find the output of the following logic circuit. ( O – 07 )

32. What is a zener diode? Draw its symbol. ( O – 09, O-10, O – 11)

Zener diode is a reverse biased, heavily doped semiconductor (silicon or germanium) PN junction

diode, which is operated exclusively in the breakdown region.

33. Give the circuit diagram of NOT gate using a transistor. ( J - 10, O – 11, O- 13, J - 15 )


34. Give the Boolean equation for the given logic diagram. ( J – 11 )

35. Prove the Boolean equation ( A + B ) ( A + C ) = A + BC ( M - 11, O - 12, O - 14 )

36. Draw the circuit diagram of difference amplifier using operational amplifier. ( J – 11 )

37. Define: bandwidth of an amplifier. ( J – 12, O – 12 )

Bandwidth is defined as the frequency interval between lower cut off and upper cut off

frequencies.

38. What are universal gates? Why they are called so? ( J – 12, O – 13 )

NAND and NOR gates are called universal gates because they can perform all the three basic

logic functions i.e. the functions of OR, AND and NOT gates.

39. For a transistor to work, how is the biasing provided? ( J – 12)

i) The emitter- base junction is forward biased so that majority charge carriers are repelled from the

emitter and the junction offers very low resistance to the current

ii) The collector-base junction is reversed biased so that it attracts majority charge carriers and this

function offers a high resistance to the current.

40. Collector current Ic=25 mA and base current Ib = 50 μA. Find current gain β of a transistor.

( O – 12, M – 13, O - 15 )

β = I C / I B α = β / 1 + β = 25 X 10

-3 / 50 X 10

-6 = 500 / 501

= 500 = 0.998

***** BEST WISHES *****


+2 Physics Unit - 10 Communication Systems Three marks Q & A

1. Define: modulation factor in amplitude modulation.

( M – 06, J – 08, O -09, M – 10, J – 11, J – 13, M – 15 )

The ratio of the change in amplitude of the carrier wave after modulation to the

amplitude of the unmodulated carrier wave.

Amplitude change of the carrier wave after

modulation

Modulation factor m = -------------------------------------------------------------------

Amplitude of the carrier wave before modulation

2. Write any three applications of RADAR. ( J – 07 )

1. Air and sea navigation is made safe

2. Radar system is used for safe landing of air crafts.

3. Pulses can be used for discovering the position of buried metals, oils and ores

3. What is FAX? Give its uses. ( O – 06, O – 14 )

1. It is an electronic system for transmitting graphical information by wire or radio.

2. To send the printed material by scanning and converting it into electrical

signal.

3. These signals are modulated and transmitted over the telephone lines.

4. What are the advantages of digital communication? ( M – 07, J – 10, M – 13 )

Advantages of digital communication:

i) The transmission quality is high and almost independent of the distance

between the terminals.

ii) The capacity of the transmission system can be increased.

iii) Light beams in optical fibers and wave guides use digital communication.


5. What is meant by skip distance?

( J – 07,M – 08,J–09, O – 10,M – 11,J – 12,O – 13, M–14, O - 15 )

Skip Distance:

In the sky wave propagation, for a fixed frequency, the shortest distance

between the point of transmission and the point of reception along the surface is

known as the skip distance.

6. What is MODEM?

MODEM :

MODEM is Modulator and Demodulator.

Modem is used to convert digital signals into analog signals capable of

being transmitted over telephone lines. At the receiving end of the system, modem

is used to demodulate the analog signals and reconstruct the digital output.

7. What is the necessity of modulation? ( O – 07 )

1. Audio frequency (20-20000Hz) is not having large amount of energy and can not be

sent over long distances.

2. Radiation of electrical energy is practically available only at high frequencies.

3. The audio signal is superimposed on high frequency carrier wave and the audio

signals are modulated.

8. Give any three advantages of optical fiber communication. ( O – 08, J – 15 )

1) Transmission loss is low.

2) Fiber is lighter and less bulky.

3) More information can be carried by each fiber.

9. What are the advantages of frequency modulation? ( M – 09 )

Advantages:

1. Noiseless reception.

2. Operating range is large.

3. Efficiency of the transmission is very high.


10. What is skip zone ? ( J – 14 )

The region between the point where there is no reception of ground waves

and the point where the sky wave is received first is called as skip zone.

11. What are the different types radio wave propagation ? ( O – 11 )

1) Ground ( surface ) wave propagation.

2) Space wave propagation.

3) Sky wave propagation.

12. Define : amplitude modulation. ( M – 12 )

The amplitude of the high frequency carrier wave is changed in accordance

with the intensity of the signal wave is called as amplitude modulation.

13. What is interlaced scanning ? ( O – 12 )

1. In interlaced scanning, during the first field odd lines are scanned and during

the second field even lines are scanned.

2. After completing the bottom of the first field, the vertical trace returns the

scanning beam to the top of the image and completes the unfinished lines.

3. Remaining even numbered lines then scanned during second field.

* *

** **


*****

Prepared by:

B.ELANGOVAN. M.Sc., M.Ed., M.Phil., ( Dr Radhakrishnan Tamil Nadu Best Teacher Award - 2011 recipient)

Post Graduate Teacher in Physics,

Pachaiyappa’s Hr.Sec.School,

Kanchipuram - 631501.

Phone: 9444438464

e-mail: [email protected]

***********


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