CHAPTER-I

INTRODUCTION TO ELECTRICAL ENGINEERING & NETWORK ANALYSIS

1. Flow of electronics in a circuit constitute. [ ] a. Magnetic charge b. an emf c. an electric current d. an electric charge

2. Wihich is the best conductor of electricity [ ] a. Carbon b. silver c. copper d.Iron

3. Lenz’s law is consequence of the law of conservation of [ ]a. Energy b. charge c. Induced emf d. Induced current

4. The direction of induced emf in a conductor is deduced y. [ ]a. Flemings left hand rule b. Fleming’s right hand rule b. c. Cork screw rule d. Lenz’s Law

5. The relation between electrical energy, voltage and charge is. [ ]a. E=Q/V b. E=QV2 c. E=QV D. E=Q/V2

6. Form Factor is the ratio of [ ]

A) RMS Value/Peak Value B) Mean value/Peak value C) RMS value/Mean Value D)Mean Value/RMS Value

7. A60Hz power line voltage of 120V is applied across a resistance of 10 ohms. The RMS value of current [ ]

A) 168A B) 8.48A C) 16.8A D) 12A

8. The standard supply frequency in India is ____________ Hz. [ ] (a) 25 (b) 50 (c) 60 (d) 100

9. A Circuit having neither any energy source nor emf source is called the _______ circuit. [ ] (a) Unilateral (b) Bilateral (c) Passive (d) Active

10. OHM is the unit of following except [ ] A) Resistance B)Capacitance C)Capacitive reactance D)Inductive reactance

11. Ohm’s law is applicable to _________ [ ] (a) Semiconductors (b) Electrolytes (c) Arc Lamps (d) None

12. The maximum efficiency of power transfer to the load is _____ % [ ] (a) 25 (b) 50 (c) 75 (d) 100

13. An alternating current is given by i=200 Sin(314t+π/3)amps. The maximum value & frequency of the current are __________ [ ] (a) 200A, 50Hz (b) 100√2A, 50Hz (c) 200A,100Hz (d) 200A,25Hz

14. Out of the following which is not a poor conductor [ ]a. Copper b. carbon c. cast iron d. tungsten

15. A 5ohm resistor having 2A current it will dissipate the power of [ ]a. 2.5w b.7 w c.10w d. 20w

16. In a circuit 30 ohm resistor carry a current 2A the voltage across the resistor is [ ]a. 15V b.30V c.60V d.130V

17. Which bulb will have minimum resistance [ ]a. 110V, 60W b. 110V, 100W c. 220V, 60W d. 220V,100W

18. Capacitance is expressed in [ ]

a. Ohms b. Henry/weber c . coulombs/volt d. volts/coulomb

19. Maximum power transferred from source when load resistance is. [ ]a. equal to source resistance b. equal to zero c. none

20. superposition theorem is applicable only for [ ]a. linear circuits b.non-linear circuits c. both linear and nonlinear circuits d. none

21. maximum power transfer occurs at a ……….. [ ]a. 100% efficiency b. 50% efficiency c. 25% efficiency d. 75% efficiency

22. The maximum power transfer theorem can be applied [ ]a. Only to DC circuits b. Only to AC circuits b. c. To both AC and DC circuits d. neither of the two

23. The internal resistance of an ideal voltage source is [ ] A) Zero B)infinity C)a finite value D)none of the above

24. The maximum power transfer theorem can be applied [ ] A) Only to DC circuits B) Only to AC circuits C) To both DC &AC circuits D) neither of the two

25. A Y arrangement of resistances has each resistance of 3Ω. The equivalent delta arrangement will have each resistance of values ______________ Ω. [ ]

(a) 9 (b) 6 (c) 3 (d) 1

26. The length of a phasor in a phasor diagram normally represents the __ values of the alternating quantity. [ ]

(a) Effective (b) Average (c) Peak (d) None

27. The capacitance of a parallel plate capacitor is not affected by _______ [ ]

(a) Area of Plates (b) Thickness of plates (c) Separation between plates (d) Nature of Dielectric.

28. While determining RTH in thevinins and Norton’s equivalent _________ [ ]

(a) Only current sources are made dead (b) Only voltage Voltage sources are made dead (c) All independent sources are made dead. (d) All current & voltage sources are made dead.

29. Kirchhoff’s laws are valid for __________ circuits. [ ] (a) Linear (b) Passive time invariant

(c) Non Linear (d) both Linear & Non Linear

30. Out of the following which is not a poor conductor [ ]a. Copper b. carbon c. cast iron d. tungsten

31. A 5ohm resistor having 2A current it will dissipate the power of [ ]a. 2.5w b.7 w c.10w d. 20w

32. In a circuit 30 ohm resistor carry a current 2A the voltage across the resistor is [ ]a. 15V b.30V c.60V d.130V

33. Which bulb will have minimum resistance [ ]a. 110V, 60W b. 110V, 100W c. 220V, 60W d. 220V,100W

34. The time period of a sinusoidal with 200Hz frequency will be__________________________35. Current magnification occurs in___________________________36. An alternating current is represented as i=70.7Sin (520t+π/6). The frequency & RMS value of

the current are __________Hz, _______A. 37. The no load current in a transformer lags the applied voltage by _____38. Maximum power transferred from source to the load when_____________39. The standard supply frequency in India is ____________ Hz.40. The capacitive reactance of a circuit __________ with the increase if frequency. 41. If rated Dc voltage is applied instead of AC to the primary of a transformer then _________ of

the transformer will burn. 42. A Sinusoidal voltage varies from Zero to maximum of 250V. The voltage at the instant of

60o of the full cycle will be ____________43. In Thevenins equivalent circuit resistance is in________________________with thevenins

voltage source 44. Capacitance is the property of a circuit element to ____________ 45. The best conductor of electricity is __________________ 46. In series combination C equivalent =___________________

CHAPTER-2

ALTERNATING QUANTITIES1. The peak value of the sine wave is 400V. its average value is [ ]

a. 254.8V b. 282.8V c. 400V d. 565.6V

2. Which of the following circuit will have the zero p.f. ? [ ]a. Inductance b. capacitance c. resistance d. both ( a) and ( b)

3. For a triangular wave the form factor is [ ]a. 1.20 b. 1.15 c. 1.11 d. 1.05

4. In purely inductive circuit [ ]a. Reactive power is zero b. apparent power is zero c. actual power is zero d. none

5. Which of the following wave has a least value of form factor [ ]

a. Triangular wave b. square wave c. sine wave d. rectangular wave

6. RMS value and average values are same in case of [ ]a. Triangular wave b. square wave c. sine wave d. rectangular wave

7. The phasor combination of resistive power and reactive power is called [ ]a. True power b. apparent power b. c. reactive power d. average power

8. Apparent power is expressed in [ ]a. Volt-ampers b. watts c. volt-ampere or watts d. VAR

9. A power factor of 1 indicates [ ]a. Purely resistive circuit b. purely reactive element c. both a and b d. none

10. The net reactance of series RLC circuit at resonance is [ ]a. Zero b. resistance c. impedance d. capacitance

11. For parallel resonance circuit the net sucseptance is [ ]a. Maximum b. minimum c. zero

12. Current magnification occurs in [ ]A. series resonance circuit b. parallel resonance circuit c. both a and b

13. voltage magnification is occurs in [ ]a. series resonance circuit b. parallel resonance circuit c. both a and b

14. if the Q factor of a series circuit is high [ ]a. the pass band is narrow b. bandwidth is more c. the pass band is wide

15. In a balanced three phase load the power factor the three phases will be [ ]a. Different b. same c. zero

16. The power factor of the DC circuit is always [ ]a. Zero b. unity c. less than unity d. greater than unity

17. A current of 100mA through an inductive reactance of 100ohm produces a voltage drop of [ ]

a. 1V b. 6.28V c. 10V d. 100V

18. To which component in an RC circuit is the power dissipation due? [ ]a. Capacitance b. resistance c. both

19. In certain RC circuit, the true power is 2W and the reactive power is 3.5 VAR. What is the apparent power? a. 3.4 VA b. 2 VA c. 4.03 VA d. 3 VA

20. If load is purely resistive and the power is 5W, what is the apparent power?a. 10 VA b. 5 VA c. 25 VA d. 50 VA

21. If Pi be the iron losses and Pc be the copper losses on full load, then the condition for

obtaining the maximum efficiency at 3/4th full load is ___________ 22. A transformer can have Zero regulation at ___________ power factor. 23. The chemical used in breather is ________.24. The power consumed in an AC circuit will be minimum when the phase difference between

current & applied voltage is _______o.

25. The symbol ‘j’ represents _____ rotation of the phasor _____ degrees.

CHAPTER 3

TRANSFORMERS1. The two windings of a transformer is [ ]

(A) Conductively linked. (B) Inductively linked.(C) Not linked at all. (D) Electrically linked.

2. If a transformer primary is energised from a square wave voltage source, its outputvoltage will be [ ]

(A) A square wave. (B) A sine wave.(C) A triangular wave. (D) A pulse wave.

3. In a transformer the voltage regulation will be zero when it operates at [ ](A) Unity p.f. (B) Leading p.f.(C) Lagging p.f. (D) Zero p.f. leading.

4. The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 HzSupply. The secondary output voltage will be [ ]

(A) 3.6 V. (B) 2.5 V .(C) 3.0 V. (D) 6.0 V.5. The emf induced in the primary of a transformer [ ]

(A) is in phase with the flux. (B) Lags behind the flux by 90 degree.(C) Leads the flux by 90 degree. (D) Is in phase opposition to that of flux.

6. A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance across the secondary. Assuming 100% efficiency, the primary current equals [ ]

(A) 0.2 Amp. (B) 5 Amps .(C) 10 Amps. (D) 20 Amps.

7. The efficiency of a transformer is mainly dependent on [ ](A) Core losses. (B) Copper losses. (C) Stray losses. (D) Dielectric losses.

8. Two transformers operating in parallel will share the load depending upon their(A) Rating. (B) Leakage reactance. (C) Efficiency. (D) Per-unit impedance.

9. No load current in a transformer: [ ](A) lags the applied voltage by 90ᵒ

(B) lags the applied voltage by somewhat less than 90ᵒ

(C) leads the applied voltage by 90ᵒ

(D) leads the applied voltage by somewhat less than 90ᵒ

10. If the full load copper losses of a transformer is 1600W, its cu loss at half-full load would be

[ ]a. 100W b. 400W c. 800W d. 640W

11. If an ammeter in the secondary of a 100/10V transformer readsn10A, what would be the current in the primary [ ]

a. 1A b.2A c.10A d.100A12. The full load rating of a transformer is 90KW at power factor 0.9. its KVA rating would be

[ ] a.70 KVA b. 86.6 KVA c. 100 KVA d. 150 KVA

13. Which of the transformer is most subjected to damage from over heating [ ]a. Iron core b. copper winding c. winding insulation d. frame or case

14. In a two winding the resistance between primary and secondary should be [ ]a. Zero b. 500ohms c. nearly 2K d. infinity

15. If a transformer is switched on to a voltage more than the rated voltage [ ]a. Its p.f. will deteriorate b. its p.f. will prove c. there will be no effect on its p.f.

16. Most widely used insulating and cooling transformer liquid is [ ]a. Askarel b. water c. mineral oil d. none

17. The efficiency of a given transformer is maximum when [ ]a. It runs over load b. it runs at half full load c. its cu loss= iron loss

18. When a 50Hz transformer is operated at 400Hz its KVA rating is [ ]a. Un effected b. reduced to 1/8 c. increased to 8timesb. D. determined by load on secondary

19. Short circuit test provides [ ]a. Cu losses of a transformer b. iron losses of a transformerb. C. cu and iron losses d. none of the above

20. Iron losses of a transformer are measured by [ ]a. Low p.f. wattmeter b. unity p.f. wattmeter c. any type of wattmeter

21. Which of the following wattmeter measure cu losses of a transformer [ ]a. Low p.f. wattmeter b. unity p.f. wattmeter c. any type of wattmeter

22. The transformation ratio of a 100KVA, 11KV/110V, 50Hz transformer will be [ ]a. 10 b.100 c. 100KVA×11KV/110V d. none

23. The amount of leakage flux of a transformer windings depends upon [ ]a. Mutual flux b. turns ratio c.the load connected d. the applied voltage

24. Transformer oil is used as [ ]a. Inert medium b. both insulant and coolant c. coolant only d. insulant only

25. Distribution transformers have a core losses [ ]a. Negligible compared to full load cu lossesb. Less compared to full load cu lossesc. Equal to full load cu lossesd. More than to full load cu losses

Chapter 4

DC & AC MACHINES

1. The armature current & field current will be equal in case of DC machines ____ [ ]a)shunt b) series c) Separately excited d)None

2. In DC generators, the residual magnetism is of the order of ______ %. [ ]a)2.5 b) 10 c) 15 d) 25

3. The current drawn by a DC motor at starting is ______ [ ]a)Zero b) Very low c) Normal d) Very high

4. The output of a dc motor depends mainly on the following two factors [ ](A)Speed and applied voltage (B) Speed and back emf.

(C)Torque and applied voltage (D) Speed and torque

5. The direction and force can in the DC motor determined by [ ]( A)Fleming’s Right hand rule (B) Lenz’s law

(C)Fleming’s Left hand rule (D) Ohm’s law

6. The d.c. series motor should always be started with load because [ ] (A) at no load, it will rotate at dangerously high speed. (B) it will fail to start.

(C) it will not develop high starting torque.(D) all are true.

7. The d.c. series motor should always be started with load because [ ](A) at no load, it will rotate at dangerously high speed. (B) it will fail to start.(C) it will not develop high starting torque.(D) all are true.

8. In a d.c. machine, the armature mmf is [ ](A) Stationary w.r.t. armature. (B) Rotating w.r.t. field.(C) Stationary w.r.t. field. (D) Rotating w.r.t. brushes.

9. The speed-torque characteristics of a DC series motor are approximately similar tothose of the _________motor. [ ]

(A) universal (B) synchronous (C) DC shunt (D) two-phase

10. The speed of a d.c. shunt motor at no-load is [ ]

(A) 5 to 10% (B) 15 to 20% (C) 25 to 30% (D) 35 to 40%

11. A d.c. shunt motor runs at no load speed of 1140 r.p.m. At full load, armature reactionweakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full load speed in r.p.m. is [ ]

(A) 1080 (B) 1203 (C) 1000 (D) 120012. In DC generators, armature reaction is produced actually by [ ]

(A) Its field current. (B) Armature conductors.(C) Field pole winding. (D) Load current in armature.

13. As compared to shunt and compound DC motors, the series DC motor will have highest torque because of its comparatively ____________ at the start. [ ]

(A) Lower armature resistance. (B) Stronger series field.(C) Fewer series turns. (D) Larger armature current.

14. The armature of a dc machine is laminated to reduce: [ ](A) Eddy current loss (B) Hysteresis loss(C) copper losses (D) friction and wind age losses

15. For a P pole lap wound armature of a DC machine, the number of parallel paths are [ ]a. 2 b.2P c. P d. P/2

16. if the field circuit of a DC shunt motor at light loads gets opened, then the motor will bea. Pick up very high speed b. slow down c. stop d. run normally

17. the three point starter is used to [ ]a.. limit high starting current b. Provide over load protectionc. provide no volt protection d. provide all the above facilities

18. A dc generator is machine that converts [ ]

A)Electrical to mechanical (B) chemical to electrical

(C)Mechanical to Electrical (D) none of the above

19. The mechanical energy source used to drive a DC generator is called a [ ]A)Alternator (B) dc motor (C) prime mover (D) rotor

20. In a dc generator the emf is induced in the [ ](A) field coils (B) Armature coils (C) commutator segments (D)brushes

21. A 12 pole, 3 phase induction motor runs at a speed of 485 rpm on a 50Hz supply. The slip of the motor is [ ]

(A)3% (B)2% (C) 4% (D) 0.15%

22. When the stator supply voltage frequency is f,then the frequency of the rotor current is [ ](A) sf (B) f (C) Zero (D)2f

23. The frequency of the rotor current in a 3 phase 50 Hz, 4 pole induction motor at full load speed is about [ ]

(A) 50 Hz. (B) 20 Hz. (C) 2 Hz. (D) Zero.

24. The power factor of a squirrel cage induction motor is [ ](A) low at light load only.(B) low at heavy load only.(C) low at light and heavy load both.(D) low at rated load only

25. When a synchronous motor is running at synchronous speed, the damper windingproduces [ ](A) damping torque.(B) eddy current torque.(C) torque aiding the developed torque.(D) no torque

26. The current from the stator of an alternator is taken out to the external load circuitThrough [ ](A) Slip rings. (B) Commutator segments.(C) Solid connections. (D) Carbon brushes

27. A motor which can conveniently be operated at lagging as well as leading powerfactors is the(A) squirrel cage induction motor. (B) Wound rotor induction motor.(C) synchronous motor. (D) DC shunts motor.

28. An alternator is delivering rated current at rated voltage and 0.8 power-factor laggingcase. If it is required to deliver rated current at rated voltage and 0.8 power-factorsleading, the required excitation will be [ ](A) less. (B) more. (C) more or less. (D) the same.

29. A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number ofPoles of the motor are [ ](A) 4. (B) 6. (C) 12. (D) 8.

30. The rotor frequency for a 3 phase 1000 RPM 6 pole induction motor with a slip of0.04 is________Hz(A) 8 (B) 4 (C) 6 (D) 2

31. A synchronous motor is operating on no-load at unity power factor. If the fieldcurrent is increased, power factor will become [ ]

(A) Leading & current will decrease(B) Lagging & current will increase.

(C) Lagging & current will decrease.(D) Leading & current will increase.

32. the efficiency of turbo-alternator _______________with increase in speed.a. decreases b. increases c. remains unchanged d. none of the aove

33. In an alternator, the effect of armature reaction is minimum at power factor ofa. 0.8666lag b. 0.866lead c. 0.5 lag d. unity

34. The power factor of the alternator determined by its a. speed b. load c. excitation d. prime mover

35. In a DC machine, the angle between the stator & rotor field is ____________. 36. Maximum torque in a DC motor is limited by __________ . 37. In a cumulatively compound DC machine, the maximum speed is fixed by _______ winding38. The type of DC motor that can be used for applications involving nearly constant speed is

………….39. The armature speed control method provides the speed control ___________ the rated speed.

40. The type of DC motor that can be used for applications involving nearly constant speed is………………….

41. When constant terminal voltage is required at the output terminals, ________________ types of DC generator is used.

42. When ‘f’ is the no. of magnetic reversals, the eddy current losses in a DC generator vary as _____________

43. The voltage of DC generator will _____ as field current decreases.44. In a motor the generated EMF is ____ than the terminal voltage.45. In an Induction motor, the torque is related to supply voltage as ___________46. The synchronous speed of a 2 pole 3 phase induction motor for supply frequency of 60 Hz

is…………………….47. The law of working principle of DC generators is _____________________. 48. The maximum torque developed by an induction motor depends upon the____________ of

the rotor.49. The synchronous speed of 3f induction motor is having 6-poles and running at 970 rpm when

connected to 50Hz supply is…………….

CHAPTER-5

BASIC INSTRUMENTS

1. In an indicating instrument, the control torque is necessary for [ ](A) Accurate measurement (B) Causing deflection of the system (C) Steady deflection (D) Damping

2. Moving iron instruments can be used for the measurement of the [ ]A) ac only (B) dc only (C) ac and dc (D) rectified ac

Am ohm-meter is an ____ type instrument. [ ]

a) Dynamo meter b) moving coil c) Moving iron d) Induction

3. A meter that is capable of measuring DC only is ____ [ ]

a) Moving Coil b) Moving Iron c) Thermo Couple d) None

4. The ammeter is ………………….instrument [ ]a. An indicating b) an integrating c) a recording d)none

5. The pointer of the indicating instrument is generally made of [ ]a) Copper b) aluminum c) silver d) soft steel

6. Dynamometer type instruments can be used for [ ]a) A.c. work only b) d.c. work only c) both d.c.and a.c.work d)none

7. A Dynamometer type instruments is chiefly used as a [ ]a) D.c. ammeter b) d.c. voltmeter c)wattmeter d) none

8. Moving iron instruments have ……………….. scale [ ]a) Uniform b) squared c) log d) none of the above

9. In a Dynamometer type instrument damping is provided by [ ]a) Air friction b) eddy currents c) fluid friction d) none

10. The range of moving iron a.c. ammeter is extended by [ ]a) A shunt b) a multiplier c) change number of operating coil d)none

11. ………………instruments are more sensitive [ ]a. Moving iron b. hot wire c. dynamometer d. PMMC

12. Which is integrated instrument [ ]

a. Voltmeter b. wattmeter c. energy meter d. power factor meter

13. Which of the following can be used for d.c. only [ ]A. Moving iron attraction type b.moving iron repulsion typeB. c. permanent magnet type d. hot wireC.

14. Which of the following can e used for measuring a.c. only [ ]a. Moving coil dynamometer type b. induction type c. moving iron type d. none

15. Which of the instrument has identical identical calibration for A.C. and D.C. values [ ]a. Induction b. Hot wire c. rectifier d. none of the above

16. Which of the following instrument is free from error in needing due to wave form [ ]

a. Induction b. Hot wire c. rectifier d. none of the above

17. A repulsion type voltmeter when used in a.c. circuits indicates [ ]a. Mean value b. peak value c. r.m.s. value d. equivalent d.c.value

18. PMMC instruments normally use [ ]a. Eddy current damping b. air friction dampingb. r.m.s. value d. equivalent d.c. value

19. An instrument that measures electrical energy is an ____ type instrument. 20. When the instrument is over damped it will become ____ 21. The material generally used for the control spring is ________________________.22. Dynamometer type of wattmeter is used for the measurement of the

_____________quantities.23. The most efficient damping can be obtained by using______________.24. In an indicating instrument, the deflecting torque is produced by using the__________

effect