Quiznetik

Physics | Set 8

1. The resistance of a conductor is inversely proportional to its -

Correct : C. area of cross section

2. is the perpendicular distance between point of application of force and axis of rotation.

Correct : A. Moment arm

3. For which one of the following, "Diodes' are generally used for?

Correct : A. Rectification

4. An object is placed on the principal axis of a convex lens of focal length 10 cm. If the distance of the object from the lens is 30 cm, what is the distance of the image formed?

Correct : B. 15 cm

5. A moving neutron collides with a stationary α-particle. The fraction of the kinetic energy lost by the neutron is –

Correct : D. 16/25

6. Which of these waves can be polarized?

Correct : D. Light waves

7. X-rays are –

Correct : C. neutral particles

8. Which of the following is the second largest source of global energy?

Correct : C. Renewable Energy

9. Which of the following methods will separate water from muddy water?

Correct : D. Filtration

10. An a-particle is           .

Correct : B. A helium nucleus

11. What type of lens is used to correct vision of a person suffering from Myopia?

Correct : B. Concave lens

12. What is the name of the device used to convert alternating cur-rent into direct current?

Correct : C. Rectifier

13. A light year is a unit of:

Correct : B. Distance

14. The SI unit of luminous emittance is -

Correct : A. Lux

15. Total internal reflection can not take place when light goes from –

Correct : B. water to glass

16. Hertz is a unit for measuring –

Correct : B. Frequency of waves

17. The unit of Planck's constant is –

Correct : A. Js

18. If a wire of resistance R is melted and recast to half of its length, then the new resistance of the wire will be -

Correct : A. R/4

19. Clouds float in the atmosphere because of their –

Correct : B. low density

20. Which of the following phenomenon is responsible for the movement of water in plants?

Correct : D. Both (2) and (3)

21. Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?

Correct : A. Scattering

22. Removal of carbon particles from air involves the principle of -

Correct : C. Electrophoresis

23. The focal length of a plane mirror is

Correct : D. Infinity

24. The wire having a green plastic covering is a               .

Correct : C. Earth wire

25. Who among the following invented battery?

Correct : C. Alessandro Volta

26. The centre of the reflecting surface of a spherical mirror is called the :

Correct : C. Pole

27. If a bomb dropped from an airplane explodes in mid-air               .

Correct : A. its KE increases

28. The phenomenon of radioactivity was discovered by -

Correct : C. Henri Becquerel

29. Energy travels from Sun to Earth through –

Correct : C. radiation

30. Rain drops acquire spherical shape due to -

Correct : B. surface tension

31. Pieces of camphor placed on water move about rapidly. This is because of -

Correct : C. surface tension

32. Which among the following is a vector quantity?

Correct : B. Angular momentum

33. What does the symbol R in electricity stand for?

Correct : D. Resistance

34. The velocity of light in vacuum is :

Correct : A. 3 * 108 ms-1

35. Why does a black board appears black in color?

Correct : D. It absorbs all the colours

36. The pitch of the sound is measured by its:

Correct : C. Frequency

37. Intensity of sound has -

Correct : A. an object existence

38. The south pole of the earth’s magnet is near the geographical                 .

Correct : D. north

39. Which among the following determines the pitch of a sound?

Correct : B. Frequency

40. Ozone layer above the surface of Earth provides a shield against –

Correct : B. Ultra-violet rays

41. The Newton's First Law is also called as –

Correct : B. Law of inertia

42. Fat can be separated from milk in a cream separator because of               .

Correct : D. centrifugal force

43. A charge of 2C passes from one point to the other in a circuit. If the potential difference between the two points is 5V, the amount of work done is :

Correct : A. 10 J

44. The large collection of Stars, dust and gas held together by gravitational attraction between components is known as

Correct : C. Galaxy

45. An amplifier is said to suffer from distortion when its output is -

Correct : C. noisy

46. While catching a ball, a player pulls down his hands to lower the -

Correct : C. impulse

47. Optical fibres are mainly used in-

Correct : A. Communication

48. Radiocarbon dating technique is used to estimate the age of -

Correct : D. fossils

49. 'Parsec' is the unit measurement of -

Correct : B. Astronomical distance

50. Receptors used to detect taste are known as -

Correct : A. Gustatory receptors

51. When a body is immersed in a liquid, the force acting on it is –

Correct : D. Both (1) and (2)

52. Tesla is a unit of magnetic –

Correct : D. field

53. The damage of the human body due to radiation (X-rays or y-rays etc,) is measured in –

Correct : A. Rems

54. Golden view of sea shell is due to -

Correct : C. Polarization

55. An object covers distance which is directly proportional to the square of the time. Its acceleration is –

Correct : D. constant

56. What is impulse equal to?

Correct : A. Change in momentum

57. The person suffering from “myopia” cannot see the objects at:

Correct : B. Longer distance

58. Which one of the following is a non- dimensional quantity?

Correct : B. Strain

59. When water freezes its density –

Correct : A. Decreases

60. Which of the following is the unit of perceived loudness of sound?

Correct : B. Sone

61. The element required for Solar energy conversion -

Correct : B. Silicon

62. The washing machine works on the principle of –

Correct : D. Centrifugation

63. The 'Choke' used with a tube light is basically –

Correct : A. an inductor

64. The temperature of a liquid is 32° F. What is its temperature in Celsius scale?

Correct : B. 0° C

65. Which of the following phenomenon helps to conclude that light is a transverse wave?

Correct : C. polarization

66. Plank's constant has the dimensions of

Correct : A. energy

67. When number of turns in a coil is trippled, without any change in the length of coil, its self inductance becomes?

Correct : A. Nine times

68. The abbreviation LHC stands for which machine?

Correct : B. Large Hadron Collider

69. Which of the following have the same unit?

Correct : C. Work and torque

70. In a particular system, the units of length, mass and time are chosen to be 10 cm, 10 g and 0.1 s respectively. The unit of force in this system will be equivalent to –

Correct : A. 0.1 N

71. Relative humidity is expressed as –

Correct : C. Percentage

72. Why is weightlessness experienced while orbiting the earth in space ships?

Correct : D. None of these

73. Where is a transistor most likely to be found?

Correct : C. Hearing aid

74. What is the SI unit of electric current?

Correct : A. Amperes

75. An object is in static equilibrium when it is           .

Correct : A. at rest

76. Equal volumes of different gases at any definite temperature and pressure have-

Correct : D. equal no. of molecules

77. Which law states, "The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings"?

Correct : B. Newton's law of cooling

78. Which of the following reaction is the main cause of energy radiated from Sun?

Correct : B. Nuclear fusion

79. Every hot object emits –

Correct : C. Infrared rays

80. Postage Meter was invented by -

Correct : B. Arthur Pitney

81. A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will -

Correct : A. increase

82. When two semiconductors of p-and n- type are brought in contact, they form p-n junction which acts like a/an –

Correct : C. Rectifier

83. Ohm's law is valid in case of –

Correct : B. conductor

84. The freezing point of fresh water is -

Correct : D. 0°C

85. The unit of noise pollution (level) is –

Correct : A. decibel

86. The boiling point of water decreases at higher altitudes is due to –

Correct : B. low atmospheric pressure

87. The reactivity of an ionic compound element is explained as its tendency to attain noble gas configuration. How do the elements do so?

Correct : C. Both are correct

88. For a ray of light to suffer total internal reflection it has to pass from –

Correct : C. air to water

89. For which of the following substances, the resistance decreases with increase in temperature?

Correct : C. Nichrome

90. A solid needle placed horizon-tally on the surface of the water floats due to –

Correct : C. surface tension of water

91. The first equation of motion gives the relation between :

Correct : C. Velocity and time

92. What is the minimum distance (in metres) required to hear an echo?

Correct : C. 17

93. The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?

Correct : D. 5 : 3

94. Which of these travels in glass with minimum velocity?

Correct : B. violet light

95. The phenomenon which causes mirage is –

Correct : D. Total internal reflection

96. Which of the following is indicated by the colour of a star?

Correct : C. temperature

97. For which one of the following, 'Diodes' are generally used for?

Correct : A. Rectification

98. Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –

Correct : B. Convection

99. Which one among the following components is used as an amplifying device?

Correct : D. Transistor

100. The commonly used coolant in refrigerators is –

Correct : C. Freon