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CNS: GEAS 2
1. Which of the following radiations will produce electron with highest energy?A. Visible Light C. X-raysB. Ultraviolet light D. Gamma rays
ANSWER: Gamma Rays
2. Two twins are 25 years old when one of them sets out on a journey through space at nearly constant speed. The twin in the spaceship measures time with an accurate watch. When he returns to earth, he claims to be 31 years old, while the twin left is then 43 years old. What was the speed of the spaceship?
A. 3.83x108 m/s C. 2.8383x108 m/sB. 1.5683x108 m/s D. 4.5383x108 m/s
SOLUTION:The spaceship clock reads the trip to be only 6 years long, while the
earth clock reads it to be 18 years. Then using time dilation formula:
; = time moving clock
; = time of stationary clock
= 0.943c
= 2.83x108 m/s
ANSWER: 2.83x108 m/s
3. The flow of heat from a hot to a cold body is an example of A. adiabatic process C. reversible processB. irreversible process D. isothermal process
ANSWER: irreversible process
4. How fast is an object moving if its apparent mass is to be 1 percent larger than its rest mass.
A. 4.2x107 m/s C. 5.2x107 m/sB. 2.2x107 m/s D. 3.2x107 m/s
SOLUTION:
We make use of the formula to obtain
Solving gives = 0.14c = 4.2x107 m/s
ANSWER: 4.2x107 m/s
5. A heat engine with 100% of efficiency would have to A. do no work C. use no heatB. be at a uniform temperature D. discharge at 0ºC
ANSWER: discharge at 0ºC
6. The process in which no heat enters or leaves the system is termed asA. isochoric C. isothermalB. isobaric D. adiabatic
ANSWER: adiabatic
7. Two reversible engines A and B have their sources at 800 and 640K. Their sinks are at 400K and 300K respectively
A. A is more efficient than BB. A is less efficient than BC. They are equally efficientD. Their efficiencies depend only upon the type of fuels used
ANSWER: A is less efficient than B
8. A hole is to be punched out of a plate having an ultimate shearing stress of 300MPa. If the compressive stress in the punch is limited to 400MPa. Determine the maximum thickness of plate from a hole 100mm in diameter can be punched.
A. 22.23 mmC. 33.33 mm*C. 23.44 mmD. 42.55 mm
SOLUTION:
Stress
= 1,000,000r N
From shearing of plate:
ANSWER: 33.33 mm
9. A cylindrical pressure vessel is fabricated from steel plates which have thickness of 20 mm. The diameter of the pressure vessel is 500 mm and its length is 3 m. Determine the maximum internal pressure which can be applied if the stress in the steel is limited to 140 MPa.
A. 12.4 MPa C. 11.2 MPaB. 15.6 MPa D. 17.9 MPa
SOLUTION:
ANSWER: 11.2 MPa
10. Compute the apparent mass of an electron traveling at half the speed of light.A. 1.05x10-30 kg C. 2.05 x10-30 kgB. 1.50 x10-30 kg D. 2.50 x10-30 kg
SOLUTION:The rest mass of an electron is 9.1 x10-31 kg. Then
ANSWER: 1.05x10-30 kg
11. Compute the speed of sound in neon gas at 27ºC. For neon, N=20.18kg/kmol.A. 293 m/s C. 454 m/sB. 156 m/s D. 544 m/s
SOLUTION:
Neon being monoatomic gas, has
Thus,
ANSWER: 454 m/s
12. The volume strain for a constqatn applied force increases directly with an increase in
A. volume C. surface areaB. compressibility D. bulk modulus
ANSWER: compressibility
13. An explosion occurs at a distance of 6.0 km from a person. How long after the esplosion does the person hear it? Assume the temperature is 14ºC.
A. 12.6 s C. 17.6 sB. 21.5 s D. 10.7 s
SOLUTION:Because the speed of sound increases by 0.61 m/s for each ºC rise in
temperature, we havev = 331 m/s + 0.61(14)v = 640 m/s
Using s = vt, we find that the time taken is
ANSWER: 17.6 s
14. A property of matter that is often used by chemis as an “identification tag” for s asubstance.
A. mass C. volumeB. specific gravity D. density
ANSWER: density
15. The mass of an alpha particle is how many times more than that of the αelectron?
A. 3500 times C. 1400 timesB. 7300 times D. 6300 times
ANSWER: 7300 times
16. What kind of chemical bond will form in binary compounds where the electronegativity difference between atoms is greater than 2.0?
A. metallic bond C. ionic bondC. covalent bon D. mechanical bond
ANSWER: Ionic Bond
17. What kind of chemical bond will form in binary compounds where the electronegativity difference between atoms is less than 1.5?
A. metallic bond C. ionic bondB. covalent bond D. mechanical bond
ANSWER: Covalent Bond
18. If the indeterminate error in weighing on a laboratory balance is 0.003 g. What size sample should you take to keep the relative error to 1.0%?
A. 0.03 g C. 0.30 gB. 1.30 g D. 2.03 g
ANSWER: 0.30 g of sampleSOLUTION:
19. What type of stress is produced whenever the applied load cause one section of a body to tend to slide past its adjacent section?
A. normal stress C. sliding stressB. shearing stress* D. bearing stress
ANSWER: shearing stress
20. The actual stress that the material has when under load is called:A. allowable stress C. working stressB. proportional limit D. rupture stress
ANSWER: working stress
21. What type of deformation is caused by shearing stress?A. change in area C. change in shapeB. change in volume D. angular change
ANSWER: change in shape
22. The straight-line portion of stress-strain is actually a measure of ______ of the material.
A. elasticity C. stiffnessB. stress D. strain
ANSWER: stiffness
23. Who coined the term “energy” in 1807?A. Thomas Young C. Lord KelvinB. William Thompson D. William Rankine
ANSWER: Thomas Young
24. A process during which the entropy remains constant:A. isentropic process C. polytropic processB. entropic process D. endothermic process
ANSWER: isentropic process
25. A pure substance at absolute zero temperature is in perfect order, and its entropy is zero. This is known as: A. the zeroth law of thermodynamics C. the third law of thermodynamics
B. first law of thermodynamics D. second law of thermodynamicsANSWER: third law of thermodynamics
26. A steel rod is stretched between two rigid walls and carries a tensile load of 5000 N at 20ºC. If the allowable stress is not to exceed 130 MPa at -20ºC, what is the minimum diameter of the rod? Assume = 11.7 µm/m-ºC and E = 200GPa.α
A. 12.33 mm C. 13.22 mmB. 14.55 mm D. 16.22 mm
SOLUTION:
ANSWER: 13.22 mm
27. A solid shaft 5 m long and 104 mm in diameter is stressed to 60 MPa when twisted through 4º. Using G = 83 GPa, what power can be transmitted by the shaft at 20 rev/s?
A. 1.665 MWC. 6.155 MWB. 3.665 MWD. 7.244 MW
ANSWER: 1.665 MWSOLUTION:
28. What do you call the type of reaction in which heat is absorbed?A. endothermic C. exothermicB. redox rection D. isothermic
ANSWER: endothermic
29. The ratio between the energy dissipated in some process and the heat appears as a result is the
A. specific heat C. kilocalorieB. triple point D. mechanical equivalent of heat
ANSWER: mechanical equivalent of heat
30. The light cable supports a mass of 12 kg per meter of horizontal length and is suspended between the two points on the same level 300 m apart. If the sag is 60 m, find the length of the cable.
A. 329 m C. 139 mB. 239 m D. 429 m
ANSWER: 329 mSOLUTION:
31. The Golden Gate Bridge in San Francisco has a main span of 1280 m, a sag of 143 m, and a total static loading of 310.8 kN per linear meter of horizontal measurement. The weight of both of the main cable is included in this load and is
assumed to be uniformly distributed along the horizontal. Calculate the midspan tension in each of the main cables.
A. 233 MN C. 223 MNB. 322 MN D. 232 MN
ANSWER: 23 MNSOLUTION:
32. Two wires, A and B, are made of the same material and are subjected to the same loads. The strain is greater for A when
A. has twice the diameter of BB. A has twice as long as BC. A has twice the length and half the diameterD. A has twice the diameter and half the length
ANSWER: A has twice the length and half the diameter
33. Electron are emitted from a metal surface when light falling on it has a minimumA. energy C. wavelengthB. velocity D. change
ANSWER: energy
34. Who designed the atomic reactor?A. WilsonC. RutherfordB. FermiD. Teller
ANSWER: Fermi
35. Whenever a system is made to complete a cyclic process, the workdone during the complete cycle
A. is zero C. is negativeB. positive D. depends upon the path followed
ANSWER: depends upon the path followed
36. Streamlined objects move more easily through fluids than those of irregular shape. The reason is that
A. turbulence is decreased C. turbulence is increasedB. viscosity is increased D. viscosity is increased
ANSWER: turbulence is decreased
37. Two pieces of wire of the same material have their length in the ratio of 1:2 and diameters in the ratio of 2:1. If they are stretched by the equal force, elongation will be in the ratio of
A. 1:2 C. 1:8B. 2:1 D. 8:1
ANSWER: 1:8
38. The volume strain for a constant applied force increases directly with an increase in
A. volume C. surface areaB. compressibility D. bulk modulus
ANSWER: compressibility
39. Bernoulli’s equation includes as a special caseA. Hooke’s Law C. Newton’s third law of motionB. Toricelli’s theorem D. Archimedes’ principle
ANSWER: Toricelli’s theorem
40. In a city water system the water will flowA. from the mains to the water outletB. only if the outlet is higher than the water in the water towerC. faster from a first floor tap than from one on the third floorD. only when the water tower has been completely emptied
ANSWER: faster from a first floor tap than from one on the third floor
41. The nib of a pen is split keeping in view the phenomenon ofA. diffusion C. osmosisB. capillarity D. cohesion
ANSWER: capillarity
42. A double convex air bubble in water acts as A. converging lens C. diverging lensB. pane slab D. none of these
ANSWER: diverging lens
43. What determines longitudinal chromatic aberration of a lens?
A. Dispersive power onlyC. Focal length onlyB. Both dispersive power and focal length D. None of these
ANSWER: Both dispersive power and focal length
44. The energies of photo electrons in photoelectric effectA. changes with intensity of lightB. changes with frequency of lightC. changes with velocity of light falling as the metal surfaceD. None of the above is correct
ANSWER: changes with frequency of light
45. Which of the following functions is performed by a photocell?A. It converts chemical energy into electrical energyB. It converts magnetic energy into electrical energyC. It converts light energy into electrical energyD. It converts electrical energy into light energy
ANSWER: It converts light energy into electrical energy
46. The maximum energy of emitted photoelectron is measured byA. the largest potential difference they can traverseB. the current they produceC. the potential difference they produceD. the speed with which they emerge
ANSWER: the speed with which they emerge
47. The theory that light is emitted in discrete amounts of energy rather than in a continuous fashion is known as
A. the photoelectric effectB. the quantum theoryC. Huygen’s principleD. the electromagnetic theory
ANSWER: the quantum theory
48. Which of the following colour phenomenon is not an interference phenomenon?A. Oil spread on the surface of water exposed to extended sources of
light exhibits brilliant coloursB. Soap bubbles in sunlight show coloursC. Sky appears blue at noon but red in the evening and dawnD. Metallic surface when heated show colours
ANSWER: Sky appears blue at noon but red in the evening and dawn
49. Air bubbles in water shines because ofA. reflection C. refractionB. diffraction D. total internal reflection
ANSWER: total internal reflection
50. When a helium atom loses an electron it becomesA. an alpha particle C. a protonB. a positive helium ion D. a negative helium ion
ANSWER: a positive helium ion
51. Emission of a -particle from a nucleusβA. changes its atomic number C. changes its mass numberB. changes both the above D. None of these
ANSWER: changes its mass number
52. Which of the following propagate at the same speed as velocity of light?A. Heat waves C. Sound wavesB. Shock Waves D. -raysβ
ANSWER: Heat waves
53. The standard fixed point for calibrating a thermometer isA. the boiling point of water C. the boiling point of iceB. the temperature of steam D. the triple point of water
ANSWER: the triple point of water
54. The gas thermometer is taken as the primary standard because A. the thermometers are easily reproducibleB. readings can be accurately takenC. no corrections are necessaryD. it reproduces the thermodynamic scale
ANSWER: it reproduces the thermodynamic scale
55. The Carnot Cycle is a A. reversible cyclic process with two isotherms and two adiabaticsB. constant pressure cycleC. constant-volume cycleD. a reversible two-stroke cycle
ANSWER: reversible cyclic process with two isotherms and two adiabatics
56. The process by which nuclei emit , and - rays in order to attain stability is α β γcalled
A. radioactive disintegration C. –decayβB. radioactivity D. radioactive transmutation
ANSWER: radioactivity
57. The process by which a heavy nucleus splits up into two lighter nuclei is known as
A. fission C. fusionB. – decayα D. a chain reaction
ANSWER: fission
58. Which atomic particle is used to cause fission in an atomic reactor?A. Alpha particle C. Beta particleC. Deuteron D. Neutron
ANSWER: Neutron
59. The driver of an automobile traveling at speed ‘v’ suddenly sees a brick wall at a distance ‘d’ directly in front of him. To avoid crashing
A. it is better to turn the car sharply away from the wallB. it is better to slam on the brakesC. the choice depends on the height of the brick wallD. it is difficult to decide
ANSWER: it is difficult to decide
60. A particle having rest mass equal to that of electron but charge equal and opposite to that of electron is called
A. proton C. positronB. hyperon D. meson
ANSWER: positron
61. Which is the most massive particle?A. Deutron C. – particleαB. Neutron D. Positron
ANSWER: – particleα
62. Kelvin’s statement of the second law of thermodynamics is called the law of Degeneration because
A. all the heat supplied to the working substance is converted into workB. in heat engines, heat can be converted to mechanical energyC. some of the heat supplied to the working of substance is not availableD. the heat engine is not very efficient
ANSWER: some of the heat supplied to the working of substance is not available
63: Thermodynamics is a subject dealing with A. the motion of molecules in matterB. The macroscopic variables, such as pressure, temperature and
volumeC. the motion of atoms in matterD. the kinetic energy of molecules
ANSWER: The macroscopic variables, such as pressure, temperature and volume
64. Which of the following constitute – particles?βA. Electrons C. ProtonsB. Photons D. None of these
ANSWER: Electrons
65. Why does nuclear fission requires high temperature?A. Because all nuclear reactions absorbs heatB. The mass deficit must be suppliedC. The particles can not come together unless they move rapidlyD. The binding energy must be supplied from external sources
ANSWER: Because all nuclear reactions absorbs heat
66. Who discovered radioactivity?A. M. Curie C. BequerelB. Both the above D. None of these
ANSWER: Bequerel
67. The source of energy of the sunA. fusion of heavy nuclei C. fusion of light nucleiC. fission of light nuclei D. All of the above
ANSWER: fusion of light nuclei
68. Which of the following phenomenon is responsible for the production of shadow?
A. Interference C. DiffractionB. Polarization D. Rectilinear propagation of light
ANSWER: Rectilinear propagation of light
69. The defect in image due to oblique centric rays falling on the lens is calledA. astigmatism C. comaB. curvature of image field D. spherical aberration
ANSWER: curvature of image field
70. The burring of the image due to dispersion in lens is called
A. spherical aberration C. chromatic aberrationB. astigmatism D. curvature of image field
ANSWER: Chromatic aberration
71. When a body is acceleratedA. its velocity always changes C. its direction always changesB. its speed always changes D. its falls towards the earth
ANSWER: its velocity always changes
72. A 2000 kg truck traveling at 36km/hr strikes a tree and comes toa top in 0.1 sec. The average force on the truck during the crash is
A. 2x103 newtons C. 2x102 newtonsB. 2x104 newtons D. 2x105 newtons
ANSWER: 2x105 newtons
73. When a charged particle moves through a magnetic field, it suffers a change in itsA. charge C. energyB. mass D. direction of motion
ANSWER: direction of motion
74. Lenz’s law follows from the law of conversion ofA. mass C. chargeB. energy D. momentum
ANSWER: mass
75. If a car is moving towards you with its horn sounding, you hear a higher pitch than you would hear if the car were at rest, this is because
A. the waves travel fasterB. successive crests produced by the horn are closer to each otherC. you received successive crests more frequently even though the wave
itself is unchangedD. the motion of the car raises the frequency of the horn
ANSWER: you received successive crests more frequently even though the wave itself is unchanged
76. A tuning fork A produces 4 beats with a tuning fork B of frequency 256. A is filled at the top of the prong and the number of beats increases. What was its original frequency?
A. 260 C. 258B. 252 D. 250
ANSWER: 260
77. Neutral temperature of a thermocouple is the temperature at which A. the thermo e.m.f. changes signB. the thermo e.m.f. is maximumC. the thermo e.m.f. is minimumD. the thermo current is maximum
ANSWER: the thermo e.m.f. is maximum
78. Factor of safety may be defined byA. yielding stress/yielding stress C. working stress/yielding stressB. breaking stress/working stress D. all of the above
ANSWER: breaking stress/working stress
79. The first patented diode used as a detector for ratio signal is credited toA. Edison C. de ForestB. Fleming D. Thomson*
AMSWER: Thomson
80. A fathometer is an instrument used to measure A. velocity of sound C. frequency of soundB. depth of sea D. wavelength of sound
ANSWER: depth of sea
81. A satellite travels in a circular orbit at a speed of 20,000 km/h to stay at a constant attitude. To escape from the earth, the speed would have to be increased to
A. 28,000 km/h C. 21,000 km/hB. 40,000 km/h D. 64,000 km/h
ANSWER: 40,000 km/h
82. When a car is traveling at constant speed around a circular track, a quantity that is constant but not zero is
A. acceleration C. angular velocityB. velocity D. angular acceleration
ANSWER: angular velocity
84. Which element has the highest ionization energy?A. NaC. LiB. KD. Cs
ANSWER: Li
85. Kinetic energy of molecules is highest in A. solids C. gasesB. liquids D. solutions
ANSWER: gases