3. In case of filament lamp at higher voltages, the resistance of lamp
Correct : B. increases
4. If the connections across the resistor are reversed, then graph between
current and potential difference is
Correct : B. straight lined
5. In semiconductors upon increasing temperature, conductivity
Correct : B. increases
6. In NTC thermistor on increasing temperature, the resistance
Correct : C. decreases
7. A component that allows unidirectional current to pass through it is
Correct : D. diode
8. A rectifier converts
Correct : B. AC to DC
9. Threshold voltage at which LED emits light is
Correct : C. more than 0.6
10. Resistivity is measured in
Correct : C. ohm meter
11. Component which obeys ohm's law is called
Correct : C. Ohmic component
12. At constant temperature, resistance and cross-sectional area are
Correct : D. inversely related
13. Current and voltage are
Correct : A. directly related
14. At threshold voltage, resistance of diode
Correct : A. decreases
15. Resistance of a particular wire depends upon
Correct : A. size and shape
16. Resistance of metal is affected by
Correct : C. both A and B
17. If current and potential difference are directly related then object
follows
Correct : A. Ohm's law
18. Effect of diffraction is greatest if waves pass through a gap with width equal to
Correct : B. wavelength
19. Visible light has wavelength of
Correct : A. 5 × 10-7 m
20. From double-slit experiment, the quantities to be measured are
Correct : D. all of above
21. For destructive interference, the path difference is
Correct : A. odd number of half wavelengths
22. Constructive interference happens when two waves are
Correct : C. in phase
23. Two waves with phase difference 180° have resultant of amplitude
Correct : B. zero
24. If two waves are in phase and have same amplitude then resultant wave has
Correct : C. twice of amplitude of single wave
25. For listening radio in cars, external radio aerials are used because
Correct : B. radio waves have longer wavelength
26. When two waves meet, their displacements
Correct : A. add up
27. Splitting of white light in to constituent colors is called
Correct : D. dispersion
28. Grating element is equal to
Correct : A. nλ/sinθ
29. With diffraction grating, the angles are
Correct : B. greater
30. Extra distance travelled by one of waves compared with other is called
Correct : D. path difference
31. Spreading of wave as it passes through a gap or around an edge is called
Correct : C. diffraction
32. Fringes are referred to as
Correct : B. maxima
33. Principle of superposition can be applied to
Correct : D. all of above
34. Coherent sources emit waves that have
Correct : C. constant phase difference
35. Interference pattern of light and dark bands on screen is called
Correct : D. fringes
36. Microwaves have wavelength of about
Correct : A. 10 cm
37. In young double slit experiment, the wavelength of incident beams
should be
Correct : A. same
38. Wavelength of an incident light when it is incident normally on a diffraction grating having 3000 lines per centimeter angular separation is 10° is
Correct : C. 580 nm
39. Supply of energy depends upon
Correct : D. all of above
40. All substances have minimum internal energy at
Correct : A. absolute zero
41. Specific heat of aluminum when 26400 J of energy is supplied to 2 kg block and it's temperature rises from 20 °C to 35 °C is {{}}
Correct : D. 880 J kg -1 K-1
42. On compression, the gat gets hotter due to
Correct : A. increase in kinetic energy
43. If there is no transfer of energy between two objects then their temperature is
Correct : A. same
44. Average kinetic energy of gas molecules is proportional to
Correct : B. thermodynamic temperature
45. Celsius scale is based on properties of
Correct : D. Water
46. Energy required per unit mass of substance to raise temperature of that
substance by 1 K is called
Correct : C. specific heat capacity
47. Measure of average kinetic energy of molecules is
Correct : A. temperature
48. Energy of molecules of any substance is known as
Correct : C. internal energy
49. Due to evaporation from certain surface, it's temperature
Correct : A. falls
50. Change of liquid in to gas without boiling is called
Correct : D. evaporation
51. On heating a solid, as the separation of atoms increases the potential
energy
Correct : C. increases
52. Temperature can't be lower than
Correct : C. 0 K
53. When a substance is melted, it's temperature doesn't rise because
Correct : B. energy is used to break the bonds
54. As the object gains speed, it's G.P.E (Gravitational Potential Energy)
Correct : D. varies depending on altitude
55. If energy loss is zero then decrease in G.P.E is equal to
Correct : B. gain in kinetic energy
56. Average power of all activities of our body is
Correct : C. 116 W
57. Energy object possesses due to it's position is called
Correct : C. potential energy
58. Change in G.P.E can be written as
Correct : A. mgh
59. Efficiency of car engine is only about
Correct : B. 20%
60. Work is defined as
Correct : A. F × S
61. Energy transferred to stone of weight 10 N falling from top of 250 m high cliff is
Correct : C. 2500 J
62. If force of 1 N moves an object through 1 m, then work done is
Correct : B. 1 J
63. SI units for energy and work are
Correct : D. Joules
64. If the ball is thrown upwards, the energy changings are
Correct : A. K.E changes to G.P.E
65. 1 W is equal to {{}}
Correct : C. 1 J s-1
66. Work done by force of gravity on a satellite of 500 N at height is
Correct : A. 0 J
67. Rate of doing work is called
Correct : A. power
68. A weight-lifter raises weights with a mass of 200 kg from the ground to a height of 1.5 m, the increase in their G.P.E is