Correct : C. Weight of the balloon is less than the weight of air displaced by it
2. The term ‘equinox’ means –
Correct : C. When the day and night are of equal duration
3. After long periods of use, a grey spot develops on the inside of a bulb. This is because –
Correct : C. dust inside the bulb condenses on the top
4. The blue colour of water in the sea is due to –
Correct : A. absorption of other colours except blue by water molecules
5. Why Earth is called the blue planet?
Correct : A. Because of two-thirds surface covered by water
6. The density of a gas is maximum at –
Correct : B. Low temperature, high pressure
7. A person standing on a railway platform listens to the whistles of arriving and departing trains. The whistle heard is -
Correct : C. of higher pitch when train arrives
8. The cause for the Tsunami, as deduced by the seismologists, is –
Correct : C. Deformation of sea floor and vertical displacement of water
9. Should cars have bumpers that collapse under impact?
Correct : D. Yes, since they help to absorb the impact of a collision and keep the occupants safe
10. Light houses are places with powerful lights to :
Correct : D. guide and warn the ships coming from different directions in the ocean.
11. A bird sitting on a high tension electric wire does not get electrocuted because –
Correct : C. it does not form a closed path for the flow of current
12. A vacuum cleaner works on the principle of pressure difference. On the moon it will –
Correct : B. not work at all
13. When a body is taken from earth to moon –
Correct : B. Weight changes but mass remains same
14. Superconductors are those elements –
Correct : B. Whose resistance falls almost to zero at very low temperature
15. Ail oil drop spreads over water because
Correct : D. surface tension of oil is much smaller than that of water
16. The nature of .fuse wire is –
Correct : A. high resistance and low melting point.
17. In a railway track, two rails are joined end to end with a gap in between them because –
Correct : D. accidents due to expansion in summer can be avoided.
18. When a pall of water is swung in a vertical circle, the water does not fall out at the top of the loop when the speed is –
Correct : B. above a certain minimum value irrespective of amount of water in the pail
19. Vehicle tyres are inflated properly –
Correct : C. to avoid skidding and to minimize friction
20. Refrigeration is a process which –
Correct : B. slows down the bacterial growth
21. The function of ball bearings in a wheel is –
Correct : B. to convert kinetic friction into rolling friction
22. On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because –
Correct : C. metals are good conductors of heat
23. The apparent weight of a person in a lift which is moving down with uniform acceleration is .
Correct : C. less than the weight when the person is stationary
24. Air Quality Index is -
Correct : B. a measuring scale to show quality of air
25. It is easy to burst a gas-filled balloon with a needle than with a nail. It is because –
Correct : C. needle exerts more pressure than nail on the balloon.
26. For a body floating in water, the apparent weight is equal to -
Correct : C. Weight of the body minus weight of the liquid
27. The characteristic invalid for heat radiation is that it travels –
Correct : C. with the speed of light
28. The method of magnetization is:
Correct : A. hammering a magnet
29. Which among the following is false about work?
Correct : C. It is a vector quantity
30. Which of the following is false?
Correct : D. The earth’s crust has about 2% carbon in the form of minerals.
31. Two vectors are said to be equal if –
Correct : C. both magnitude and direction are same
32. A real gas can act as an ideal gas in -
Correct : B. low pressure and high temperature
33. The Dynamo converts –
Correct : D. Mechanical Energy into Electrical Energy
34. Winch of the following is not true about X-rays?
Correct : A. have low penetrating power
35. A Fuse wire is characterized by –
Correct : D. Low resistance and low melting point
36. Ice is packed in saw dust because –
Correct : B. saw dust is poor conductor of heat.
37. A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
Correct : C. just before it touches the ground
38. What is Hooke’s Law?
Correct : B. Stress is directly proportional to strain.
39. Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
Correct : C. Radiation and convection only
40. A drop of liquid assumes spherical shape because:
Correct : B. A sphere has the least surface area for a given volume
41. What are audible sound waves?
Correct : B. Having frequency between 20 Hz to 20000 Hz
42. Sun appears red in colour at sun-rise and sunset due to –
Correct : D. that all other colours scatter away except red
43. Why does a cannon recoil after firing?
Correct : C. NeMon's third law of motion
44. During the motion of a projectile fired from the earth surface, .
Correct : D. horizontal component of its velocity remains constant
45. A system exhibiting S.H.M. must possess –
Correct : A. Elasticity as well as inertia
46. The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
Correct : D. there is no air or any other gas in the bell jar
47. At hill stations, the boiling point of water will be –
Correct : B. less than that at sea level
48. Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
Correct : D. X-rays, infrared, visible, microwave
49. A black body can absorb radiations of
Correct : D. all wavelengths
50. The water from a hand pump is warm in winter because –
Correct : B. The temperature inside the earth is higher than the atmospheric temperature
51. When hot liquid is poured into a thick glass tumbler, it cracks because glass –
Correct : A. is a bad conductor of heat so only inner surface expands
52. Hydro-electric power is a:
Correct : D. renewable natural resource
53. The electric motor converts -
Correct : A. Electrical energy into mechanical energy
54. Burns caused by steam are much severe than those caused by boiling water because –
Correct : B. Steam has latent heat
55. According to special theory of relativity the mass of a particle –
Correct : A. increases with increase in velocity with respect to an observer.
56. Vegetables are cooked in lesser time by adding a pinch of salt while cooking because
Correct : A. boiling point of water increases
57. A man standing at the top of a tower has two spheres A and B. He drops sphere A downwards and throws sphere B horizontally at the same time. Which of the following is correct?
Correct : A. Both the spheres will reach the ground simultaneously.
58. The wavelength at which the peak of intensity of blackbody radiation Occurs –
Correct : B. decreases with increase in temperature
59. A dynamo converts .
Correct : B. Mechanical energy into electrical energy
60. If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is –
Correct : B. Surface area of the bottom of the vessel
61. What is the relation between wavelength, frequency and velocity?
Correct : A. velocity of wave = frequency * wavelength
62. Ozone layer in the outer atmosphere helps us in –
Correct : D. absorbing U-V radiations
63. Stationary wave is formed by –
Correct : D. two waves of same frequency travelling in the opposite direction
64. What is inertia?
Correct : A. Tendency to resist change in the current state
65. A good conductor while carrying current is -
Correct : B. negatively charged
66. The propagation of sound waves in a gas involves –
Correct : A. Adiabatic compression and rarefaction
67. Which of the following events occurred first?
Correct : B. Max Planck unveiled the Quantum Theory
68. Which of the following is not a property of heavy water?
Correct : A. Boiling point of heavy water is lower than that or ordinary water
69. A mirage occurs because of –
Correct : B. Total internal reflection by layers of air
70. Knot is a measure of –
Correct : A. The speed of ship
71. When the main switch of the house is put off it disconnects the –
Correct : C. live wire and the neutral wire
72. Negative feedback in amplifiers –
Correct : A. increases bandwidth and decreases noise
73. What is Hooke's Law?
Correct : B. Stress is directly proportional to strain.
74. Wollen clothes keep the body warm because –
Correct : B. Wool is a had conductor
75. Flywheel is an important part of a steam engine because it -
Correct : C. helps the engine in keeping the speed uniform
76. The bats can fly in the dark because –
Correct : C. They generate flashes of light
77. A microscope used in pathological laboratories forms –
Correct : C. Magnified, virtual and inverted image
78. It is dangerous to observe solar eclipse with naked eyes because –
Correct : B. Ultraviolet radiations from Sun burn our retina
79. The wall of a dam is broader at the base
Correct : B. to withstand pressure that increases with depth
80. A transformer –
Correct : B. is used to decrease or increase AC voltage
81. 'Mirage' is an example of –
Correct : C. refraction and total internal reflection of light
82. The absolute zero is a temperature at which .
Correct : A. molecular motion in a gas would cease
83. Surface tension in a liquid is due to :
Correct : B. Cohesive force between molecules
84. When a vehicle passes, TV reception gets distorted. This is because –
Correct : B. spark plug creates electromagnetic disturbances
85. The snow on the mountains does NOT melt all at once when it is heated by the sum because:
Correct : B. It reflects most of the heat from the sum
86. The water from a hand pump is warm in winter because -
Correct : B. the temperature inside the Earth is higher than the atmospheric temperature
87. ‘Mirage' is an example of -
Correct : C. Refraction and total internal reflection of light
88. It is easier to carry two buckets of water in one hand each, than to carry only one in one hand because –
Correct : C. centre of gravity and centre of equilibrium fall within the feet
89. Dynamo is a device for converting –
Correct : B. Mechanical energy into electrical energy
90. The magnifying power of an astronomical telescope can be decreased by –
Correct : B. increasing the focal length of the eyepiece
91. Which of the following events occurred first?
Correct : B. Max Planck unveiled the Quantum Theory
92. The velocity of sound in air –
Correct : D. decreases with decrease of temperature
93. The sensation of weightlessness in a spacecraft in an orbit is due to the –
Correct : B. Acceleration in the orbit which is equal to the acceleration due to gravity outside
94. Energy in reflected light :
Correct : B. increases with the increase in angle
95. A person standing on a railway platform listens to the whistles of arriving and departing trains. The whistle heard is –
Correct : C. of higher pitch when train arrives
96. A dynamo is a device which –
Correct : C. converts mechanical energy into electrical energy
97. A piece of paper and a cricket ball are dropped from the same height. Under which of the following conditions do both reach the surface simultaneously?
Correct : D. They must be dropped in vacuum
98. Woollen cloth protects the body from cold because –
Correct : B. it is a poor conductor of heat
99. The threshold frequency is the frequency below which -
Correct : D. photo electric emission is not possible