1. Which is an example of Phototropism ?
a) Roots of a plant following water
b) Plant bending toward the light
c) Roots growing into the soil
d) A venus flytrap capturing a fly
Explanation: Sunflowers are a great example of positive phototropism, because not only do their stems curve toward the light but their flowers turn to face the sunlight as well.
2. Light travels fastest in
a) Air
b) Water
c) Glass
d) Diamond
Explanation: Light travels fastest in air.
3. Light travels slowest in
a) Glass
b) water
c) Air
d) Vacuum
Explanation: The indexes of refraction for diamond, air and glass are, respectively, 2.42, 1.00, and approximately 1.50, depending upon the composition of the glass. Light travels slowest in diamond.
4. Light from the sun reaches us in nearly
a) 5 min
b) 4.30 hrs
c) 8 min
d) 5.30 hrs
Explanation: The light from the sun takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System varies from about 3 minutes for Mercury to about 5.3 hours for Pluto.
5.An image formed by a plane mirror, that cannot be obtained on a screen is called ________
a) Virtual image
b) Real image
c) Inverted image
d) Erect image
Explanation: A virtual image is formed when reflected rays appear to meet. Such images cannot be obtained on screen. Plane mirrors, convex mirror and concave lens always forms virtual image.
6. The boiling point of water depends upon the
a) Atmospheric pressure
b) Volume
c) Density
d) Mass
Explanation: The boiling point of water depends upon the atmospheric pressure.
7. One bar is equal to
a) 103 Pa
b) 106 Pa
c) 105 Pa
d) 104 Pa
Explanation: One bar is equal to 105 Pa.
8. Pressure Cooker cooks faster because
a) Boiling point decreases with rise of pressure
b) It cooks the food at low pressure
c) Higher temperature is attained for cooking
d) The material of the cooker is a good conductor
Explanation: Food is cooked more quickly in a pressure cooker because at the higher pressure (1 bar/15 psi), the boiling point of water rises from 100°C (212°F) to 121°C (250°F). Since less water or liquid has to be heated, the food reaches its cooking temperature faster.
9. 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
a) 0.1 N
b) 1 N
c) 10 N
d) 100 N
Explanation: Mass = 10 g = 0.01 kg
Length = 10 cm = 0.1 m
Time = 0.1 s
Force = mass × length/ time ^2
= > Force = 0.01 × 0.1 × 0.1-2 = 0.1 N
10. The weakest of all fundamental forces is
a) Gravitational force
b) Electrostatic force
c) Magnetic force
d) Nuclear force
Explanation: Gravitation is by far the weakest of the four interactions at the atomic scale, where electromagnetic interactions dominate.
11. In a railway track, two rails are joined end to end with a gap in between them because
a) Steel can be saved
b) Accidents due to contraction in winter can be avoided
c) Air-gaps are necessary for bearing the weight of running train
d) Accidents due to expansion in summer can be avoided
Explanation: In a railway track, two rails are joined end to end with a gap in between them because accidents due to expansion in summer can be avoided.
12. Air coolers are more suitable for
a) Hot and humid climate
b) Hot and dry climate
c) Cool and humid climate
d) Cool and dry climate
Explanation: Air coolers are more suitable for hot and dry climate.
13. We feel cool when we sit near the fan, this is because
a) Fan gives cool air.
b) Fan cools surrounding air.
c) Air vapourises the sweat on our body.
d) We feel cool when air touches the body.
Explanation: A fan produces a feeling of comfort because our perspiration or sweating evaporates rapidly. Our body tries to cool ourselves by releasing sweat through pores of our skin. And when we sit under the fan, the sweat of our body evaporates due to directed air upon us making our body cool.
14. When hot-water is sprinkled on a hotter glass tumbler, it breaks because
a) Glass suddenly expands
b) Glass suddenly contracts
c) Water evaporates
d) Glass reacts chemically with water
Explanation: If the poured liquid is relatively hotter or colder in comparison to the tumbler, it will break. When hot water is poured into a tumbler there is an uneven increase in the thermal expansion of the walls of the vessel.
15.A gap is left between two rails of a railway track to accommodate...... of the metal.
a) Areal expansion
b) Volume expansion
c) Linear expansion
d) Apparent expansion
Explanation: A gap is left between two rails of a railway track to accommodate linear expansion of the metal.
16. During hot weather, the fan produces a feeling of comfort. This is because
a) Fan supplies cool air
b) Fan cools the air
c) Our perspiration eva-porates rapidly
d) Conductivity of air increases
Explanation: During hot weather, the fan produces a feeling of comfort. This is because our perspiration evaporates rapidly.
17. The flow of thermal energy is called
a) heat
b) Current
c) Voltage
d) Potential
Explanation: The term conduction refers to the transfer of energy. Conduction occurs when energy is passed between objects. The transfer of thermal energy is called heat.
18. 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 :
a) Metals have higher thermal capacity than plastics
b) Plastics have a lower density than metals
c) Metals are good conductors of heat
d) Plastics have a higher thermal conductivity than metals
Explanation: 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 metals are good conductors of heat.
19. Which of the following is an insulator?
a) Mercury
b) Carbon
c) Germanium
d) glass
Explanation: Glass is an insulator.
20. 'Therm' is the unit of
a) Power
b) Heat
c) Light
d) Distance
Explanation: 'Therm' is the unit of heat.
21. Light from Sun reaches Earth in approximately
a) 3 minutes
b) 8 minutes
c) 10 minutes
d) 12 minutes
Explanation: Light from Sun reaches Earth in approximately 8 minutes.
22. Through which light cannot pass?
a) Notebook paper
b) water
c) Book
d) Sun glasses
Explanation: Light cannot pass through book.
23. The speed of light in air is
a) 3 × 108 m/s
b) 3 × 10–8 m/s
c) 8 × 103 m/s
d) Infinity
Explanation: The speed of light in air is 3 × 108 m/s.
24.Eclipses occur due to which optical phenomena?
a) Reflection
b) Refraction
c) Rectilinear propagation
d) Diffraction
Explanation: Eclipses occur due to rectilinear propagation of light.
25.When a bottle of scent is kept open in a corner of a room its odour is felt in all parts of the room. This is due to the phenomenon of :
a) Evaporation
b) Vaporisation
c) Diffusion
d) Sublimation
Explanation: When a bottle of perfume is opened in a corner of a room, the scent soon spreads all over the room. This physical procedure is called diffusion, due to which the liquid or gaseous molecules travels from the area of higher density to that of the lower density of that substance.
26. The unit of force is a
a) Derived Unit
b) Basic Unit
c) Fundamental Unit
d) None of the above
Explanation: The unit of force is a derived unit.
27. Atmospheric pressure exerted on earth is due to
a) Gravitational pull
b) Rotation of earth
c) Revolution of earth
d) Uneven heating of earth
Explanation: Atmospheric pressure is caused by the gravitational attraction of the planet on the atmospheric gases above the surface, and is a function of the mass of the planet, the radius of the surface, and the amount and composition of the gases and their vertical distribution in the atmosphere.
28. What is the SI unit of Force?
a) pascal
b) Boyle
c) Newton
d) Watt
Explanation: SI unit of force is Newton.
29. What measures Air pressure?
a) Barkometer
b) Bolometer
c) Spectrometer
d) Barometer
Explanation: Barometer measures air pressure.
30. The rice is cooked more quickly in a pressure cooker because
a) It is covered.
b) Less quantity of water is used.
c) None of these
d) Water boils at a higher temperature under pressure.
Explanation: Food is cooked more quickly in a pressure cooker because at the higher pressure (1 bar/15 psi), the boiling point of water rises from 100°C (212°F) to 121°C (250°F). The hotter steam is able to transmit its thermal energy to the food at around 4 times the rate of conventional boiling.
31. Who measured the velocity of light first ?
a) Galileo
b) Newton
c) Romer
d) Einstein
Explanation: Galileo attempted to record the time between lantern signals but was unsuccessful because the distance involved was too small and light simply moved too fast to be measured this way. Around 1676, Danish astronomer Ole Romer became the first person to prove that light travels at a finite speed.
32. Light houses are places with powerful lights to :
a) Guide and resolve traffic jams in crowded metro-cities during nights
b) Guide and help large crowds at religious gathering during nights
c) Indicate to the incoming warships, the location of a harbour during night
d) Guide and warn the ships coming from different directions in the ocean
Explanation: Light houses are places with powerful lights to guide and warn the ships coming from different directions in the ocean.
33. It is dangerous to observe Solar eclipse with naked eyes because
a) Infrared radiations from sun burn our retina
b) Ultraviolet radiations from Sun burn our retina
c) All radiations from sun initiate chemical reactions in eyes
d) Cosmic rays reach eyes more during the eclipse
Explanation: Exposing your eyes to the sun without proper eye protection during a solar eclipse can cause “eclipse blindness” or retinal burns, also known as solar retinopathy. This exposure to the light can cause damage or even destroy cells in the retina (the back of the eye) that transmit what you see to the brain.
34. Formation of shadows can be explained by
a) Rectilinear propagation of light
b) Reflection
c) Refraction
d) Total internal reflection
Explanation: Formation of shadows can be explained by rectilinear propagation of light.
35.The locomotion of insects to the source of light is called :
a) Phototropic
b) Hydrotropic
c) Phototactic
d) Thermotactic
Explanation: The locomotion of insects to the source of light is called Phototropic.
36. Which of the following is arranged in order of decreasing conductivity?
a) Copper, Aluminium, Steel, Silver
b) Aluminium, Silver, Copper, Steel
c) Copper, Silver, Aluminium, Steel
d) Silver, Copper, Aluminium, Steel
Explanation: Silver, Copper, Aluminium, Steel is arranged in order of decreasing conductivity.
37. Every hot object emits ________
a) X- rays
b) Visible light
c) Infrared rays
d) Ultraviolet rays
Explanation: Every hot object emits infrared rays.
38. Which metal is the best conductor of heat?
a) Silver
b) Gold
c) Copper
d) All of the above
Explanation: Silver is the best conductor of heat.
39. When hot liquid is poured into a thick glass tumbler, it cracks because glass :
a) Is a bad conductor of heat so only inner surface expands
b) Has high temperature coefficient of expansion
c) Has a very low specific heat
d) Has low temperature coefficient of expansion
Explanation: When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
40. Mud houses are cooler in summers and warmer in winters as compared to brick houses because
a) Mud is a good conductor
b) Mud is a bad conductor
c) Mud is a poor insulator
d) Evaporation of water causes cooling in summers and sunlight coming through holes causes warming in winters
Explanation: Clay is a poor conductor of heat as compared to wood and bricks. Therefore, clay neither allows the external heat to enter the house in summer nor it allows the internal heat to escape out in winters. Hence, mud houses remain colder in summer and warmer in winter. mud or clay is poor conductor of electricity.
41. When heated from 0 to 100oC volume of a given mass of water will :
a) Increase gradually
b) Decrease gradually
c) Increase and then will decrease
d) Decrease and then will increase
Explanation: From water at 0°C to water at 4°C, on addition of heat, the water surprisingly, contracts till it reaches maximum density at 4°C. This negative thermal expansion is termed as the anomalous expansion of water. From water at 4°C to water at 100°C, water shows a positive cubical thermal expansion like other substances and gradually expand with the increase in temperature.
42. When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of
a) Surface tension
b) Capillarity
c) Viscosity
d) Diffusion
Explanation: When a bottle of perfume is opened in a corner of a room, the scent soon spreads all over the room. This physical procedure is called diffusion, due to which the liquid or gaseous molecules travels from the area of higher density to that of the lower density of that substance.
43. Which of the following laws validates the statement that matter can neither be created nor destroyed ?
a) Law of conservation of energy
b) Le Chatelier's Principle
c) Law of conservation of mass
d) Law of osmosis
Explanation: Law of conservation of mass validates the statement that matter can neither be created nor destroyed.
44. The boiling point of liquids vary as
a) Pressure varies
b) Temperature varies
c) Volume varies
d) Density varies
Explanation: The boiling point of a liquid varies according to the applied pressure; the normal boiling point is the temperature at which the vapour pressure is equal to the standard sea-level atmospheric pressure (760 mm [29.92 inches] of mercury). At sea level, water boils at 100°C (212°F).
45.The freezing point of fresh water is ________ .
a) 4°C
b) 3°C
c) 5°C
d) 0°C
Explanation: Freezing point is the temperature where a liquid converts into solid. Water converts into ice at zero degrees centigrade. So degree zero centigrade is the freezing point of water.
46. Friction can be reduced by changing from
a) Static to Dynamic
b) Rolling to Sliding
c) Dynamic to Static
d) Sliding to Rolling
Explanation: Friction can be reduced by changing from sliding to rolling. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.
47. It is more difficult to walk on ice than on a concrete road because
a) There is very little friction between the ice and feet pressing it
b) Ice is soft when compared to concrete
c) There is more friction between the ice and feer
d) None of these
Explanation: Main thing is that we find more friction on roads than on ice. As, we can call the friction as grip on roads. We can hear the word by tyre companies as the road grip tyres. Here the grip of the tyre is more than that of any normal tyre.
48. A ball rolling along the ground gradually slows down and finally comes to rest is due to ________
a) Friction
b) Magnetic force
c) Electrostatic force
d) Muscular force
Explanation: A ball rolling along the ground gradually slows down and finally comes to rest. It is the force of friction between the surface of the ball and the ground that brings the moving ball to rest.
49. Frictional force acts in
a) The same direction as the motion
b) The opposite direction of the motion
c) All the directions
d) Upward direction
Explanation: The part which is tangent to the contacting surfaces is called the frictional force. Friction is a resisting force that acts on a body to prevent or retard its motion. Friction force always acts tangent to the surface at points of contact. Friction force acts opposite to the direction of motion.
50. The force which makes a vehicle to stop when break is applied is called
a) Gravitational force
b) Vanderwalls force
c) Frictional force
d) Covalant force
Explanation: A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction.
51. Lux is the SI unit of
a) intensity of illumination
b) luminous efficiency
c) luminous flux
d) luminous intensity
Explanation: The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m2.
52. On a rainy day, small oil films on water show brilliant colours. This is due to
a) dispersion
b) interference
c) diffraction
d) polarization
Explanation: On a rainy day, small oil films on water show brilliant colours. This is due to Interference.
Interference is a phenomenon in which two waves superimpose to form a resultant wave of greater, lower or same amplitude.
53. Point A is at a lower electrical potential than point B. An electron between them on the line joining them will
a) Move towards A
b) Move towards B
c) Move at right angles to the line joining A and B
d) Remain at rest
Explanation: Since we know that electric currents move from a higher potential or a lower potential. Also, electrons move in the direction opposite to electric current. So the electron on the line joining two points A and B will move from lower to higher potential i.e, it will move towards B.
54. Materials for rain-proof coats and tents owe their water-proof properties to
a) surface tension
b) viscosity
c) specific gravity
d) elasticity
Explanation: The material of rain proof coats have the property of not minimizing the surface tension which will tend the water molecule to be in its drop form.
55.RADAR is used for:
a) locating submerged submarines.
b) receiving a signals in a radio receiver.
c) locating geostationary satellites.
d) detecting and locating the position of objects such as Aeroplanes.
Explanation: RADAR is used for detecting and locating the position of objects such as Aeroplanes.
56. Supersonic plane fly with the speed
a) less than the speed of sound
b) of sound
c) greater than the speed of sound
d) of light
Explanation: Vehicles that fly at supersonic speeds are flying faster than the speed of sound.
57.Mach number is used in connection with the speed of
a) sound
b) aircraft
c) spacecraft
d) ships
Explanation: Mach number is used in connection with the speed of aircraft.
58. On a stationary sail boat, air is blown from a fan attached to the boat. The boat
a) moves in opposite direction in which the air is blown
b) does not move
c) moves in the same direction in which air blows
d) spins around
Explanation: In this case air blown by the fan will try to push the sail boat in a certain direction. But at the same time due to Newton's third law of motion the fan will experience a force due to the air blown in a direction opposite to the direction in which the sail boat will experience the force due to the blown air. So, as a whole the system will be at rest and it will not move.
59. Rainbow is due to
a) absorption of sunlight in minute water droplets
b) diffusion of sunlight through water droplets
c) ionisation of water deposits
d) refraction and reflection of sunlight by water droplets
Explanation: A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured circular arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.
60. Stars which appear single to the naked eye but are double when seen through a telescope are
a) novas and supernovas
b) binaries
c) asteroids
d) quasars
Explanation: They are single to naked eye because they are far from us. But, if we see with telescope We can observe that there are two or double stars.
61. Moment of inertia is:
a) Vector
b) Scalar
c) Phasor
d) Tensor
Explanation: Moment of inertia is tensor.
62. Of the following natural phenomena, tell which one known in Sanskrit as 'deer's thirst'?
a) rainbow
b) Earthshine
c) Halo
d) Mirage
Explanation: Of the following natural phenomena, mirage is known in Sanskrit as 'deer's thirst'?
63. Inside an aeroplane, flying at a high altitude,
a) the pressure is the same as that outside.
b) normal atmospheric pressure is maintained by the use of air pumps.
c) the pressure inside is less than the pressure outside.
d) normal humidity and partial vacuum are maintained.
Explanation: The air pressure in an aircraft (cabin pressure) is kept higher than the atmospheric pressure at high altitudes to avoid discomfort to passengers due to low outside air pressure. This pressure is called cabin pressurization. Hence the normal atmospheric pressure is maintained by the use of air pumps.
64. Sound travels with a different speed in media. In what order does the velocity of sound increase in these media?
a) Water, iron and air
b) Iron, air and water
c) Air, water and iron
d) Iron, water and air
Explanation: Increasing order of velocity of sound in the following media is as follows : Air, water and iron.
65.One thousand microns is equal to
a) 10-3m
b) 10-6m
c) 10-9m
d) 10-12m
Explanation: One thousand microns is equal to 10-3m.
66. Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to:
a) The heating effect of current alone
b) Hysteresis loss alone
c) Both the heating effect of current and hysteresis loss
d) Intense sunlight at noon
Explanation: Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to both the heating effect of current and hysteresis loss.
67. Nuclear sizes are expressed in a unit named
a) Fermi
b) Angstrom
c) Newton
d) Tesla
Explanation: Fermi - A unit of length equal to 10-15 meter (one femtometer), used in nuclear physics. It is similar to the diameter of a proton.
68. Light year is a unit of
a) Time
b) Distance
c) light
d) Intensity of light
Explanation: Light year is a unit of distance.
69. Mirage is due to:
a) Unequal heating of different parts of the atmosphere
b) Magnetic disturbances in the atmosphere
c) Depletion of ozone layer in the atmosphere
d) Equal heating of different parts of the atmosphere
Explanation: Mirages happen when the ground is very hot and the air is cool. The hot ground warms a layer of air just above the ground. When the light moves through the cold air and into the layer of hot air it is refracted (bent). A layer of very warm air near the ground refracts the light from the sky nearly into a U-shaped bend.
70. Light from the Sun reaches us in nearly
a) 2 minutes
b) 4 minutes
c) 8 minutes
d) 16 minutes
Explanation: The light from the sun takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface.
71. Sound of frequency below 20 Hz is called
a) audio sounds
b) infrasonic
c) ultrasonic
d) supersonics
Explanation: Sound of frequency below 20 Hz is called Infrasonic.
72. On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because:
a) mercury is a metal.
b) density of mercury is greater than that of water.
c) cohesion of mercury is greater than its adhesion with glass.
d) cohesion of water is greater than its adhesion with glass.
Explanation: On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because cohesion of mercury is greater than its adhesion with glass.
73. Suitable impurities are added to a semiconductor depending on its use. This is done in order to
a) increase its life
b) enable it to withstand higher voltages
c) increase its electrical conductivity
d) increase its electrical resistivity
Explanation: Suitable impurities are added to a semiconductor depending on its use. This is done in order to increase its electrical conductivity.
74. Stars twinkle because
a) the intensity of light emitted by them changes with time.
b) the distance of the stars from the earth changes with time.
c) the refractive index of the different layers of the earth's atmosphere changes continuously.
d) None of these
Explanation: Stars twinkle because the refractive index of the different layers of the earth's atmosphere changes continuously.
75.It takes much longer to cook food in the hills than in the plains, because
a) in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time
b) due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100oC and therefore water takes longer to boil
c) in the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere
d) in the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking
Explanation: It takes much longer to cook food in the hills than in the plains, because in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100oC causing an increase in cooking time.
76. ML2T-2 is the dimensional formula for
a) moment of inertia
b) pressure
c) elasticity
d) couple acting on a body
Explanation: ML2T-2 is the dimensional formula for couple acting on a body.
77. Solar eclipse will take place when
a) the sun is between the moon and the earth
b) the earth is between the moon and the sun
c) the moon is between the sun and the earth
d) the moon does not lie on the line joining the sun and the earth
Explanation: Solar eclipse will take place when the moon is between the sun and the earth.
78. Isotopes of an element contain
a) the same number of protons but different number of neutrons
b) the same number of neutrons but different number of protons
c) equal number of protons and electrons
d) equal number of nucleons
Explanation: Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.
79. One watt-hour is equivalent to
a) 6.3 x 103 J
b) 6.3 x 10-7 J
c) 3.6 x 103 J
d) 3.6 x 10-3 J
Explanation: One watt-hour is equivalent to 3.6 x 103 J
80. Sir C.V. Raman was awarded Nobel Prize for his work connected with which of the following phenomenon of radiation?
a) Scattering
b) Diffraction
c) Interference
d) Polarization
Explanation: The Nobel Prize in Physics 1930 was awarded to Sir Chandrasekhara Venkata Raman "for his work on the scattering of light and for the discovery of the effect named after him."
81. Sound waves in air are
a) transverse
b) longitudinal
c) electromagnetic
d) polarised
Explanation: Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. A vibrating string can create longitudinal waves as depicted in the animation below.
82. Magnetism at the centre of a bar magnet is
a) Minimum
b) maximum
c) Zero
d) minimum or maximum
Explanation: Zero
83. It is more difficult to walk on a sandy road than on a concrete road because
a) sand is soft and concreter is hard.
b) the friction between sand and feet is less than that between concrete and feet.
c) the friction between sand and feet is more than that between concrete and feet.
d) the sand is grainy but concrete is smooth.
Explanation: The friction between sand and feet is less than that between concrete and feet.
84. Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2
a) 0.14 m/s
b) 140 m/s
c) 1.4 km/s
d) 14 m/s
Explanation:
14 m/s.
85.Of the following properties of a wave, the one that is independent of the other is its
a) amplitude
b) velocity
c) wavelength
d) frequency
Explanation: The amplitude (A) is independent of other means it is not related to the other quantities.
86. Which of the following terms is not used in the field of physics?
a) Latent heat
b) Nuclear fusion
c) Refractive index
d) Stock value
Explanation: Stock value is not used in the field of physics.
87. Radiocarbon is produced in the atmosphere as a result of
a) Collision between fast neutrons and nitrogen nuclei present in the atmosphere.
b) Action of ultraviolet light from the sun on atmospheric oxygen.
c) Action of solar radiations particularly cosmic rays on carbon dioxide present in the atmosphere.
d) Lightning discharge in atmosphere.
Explanation: Radiocarbon is produced in the atmosphere as result of collision between fast neutrons and nitrogen nuclei present in the atmosphere.
88. It is easier to roll a stone up a sloping road than to lift it vertical upwards because
a) Work done in rolling is more than in lifting.
b) Work done in lifting the stone is equal to rolling it.
c) Work done in both is same but the rate of doing work is less in rolling
d) Work done in rolling a stone is less than in lifting it.
Explanation: It is easier to roll a stone up a sloping road than to lift it vertical upwards because work done in rolling a stone is less than in lifting it.
89.The absorption of ink by blotting paper involves:
a) Viscosity of ink
b) Capillary action phenomenon
c) Diffusion of ink through the blotting
d) Siphon action
Explanation: The absorption of ink by blotting paper involves capillary action phenomenon because the blotting paper is a thin and a smooth paper which allows a little thicker liquids like ink to absorb.
90. Siphon will fail to work if:
a) The densities of the liquid in the two vessels are equal.
b) The level of the liquid in the two vessels are at the same height.
c) Both its limbs are of unequal length.
d) The temperature of the liquids in the two vessels are the same.
Explanation: Siphon is a tube bent to form two legs of unequal length by which a liquid can be transferred from a reservoir and then down to a lower level of it. Siphon will fail to work if, the level of the liquid in the two vessels are at the same height.
91. Sound travels at the fastest speed in
a) steel
b) water
c) air
d) vacuum
Explanation: Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.
92. Oil raise up the wick in a lamp. The principle involves
a) the diffusion of oil through the wick
b) the liquid state of oil
c) capillary action phenomenon
d) volatility of oil
Explanation: The raise of oil up the wick in a lamp is an example of capillary action where adhesive forces are greater than cohesive forces.
93. Superconductors are substances which
a) conduct electricity at low temperature
b) offer high resistance to the flow of current
c) offer no resistance to the flow of electricity
d) conduct electricity at high temperatures
Explanation: By definition, superconductors are substances which display zero electrical resistance when a current is supplied, and are able to propagate such a current in a circuit indefinitely.
94. Light travels at the fastest speed in:
a) glass
b) water
c) hydrogen
d) vacuum
Explanation: Light travels at the fastest speed in Vacuum.
95.Railway tracks are banked on curves
a) necessary centrifugal force may be obtained from the horizontal component weight of the train
b) to avoid frictional force between the tracks and wheels
c) necessary centripetal force may be obtained from the horizontal component of the weight of the train
d) the train may not fly off in the opposite direction
Explanation: When a fast moving train takes a curved path, it tends to move away tangentially off the track. In order to prevent this, the curved tracks are banked on the outside to produce the necessary centripetal force required to keep the train moving in a curved path.
96. Out of the following pairs, choose the pair in which the physical quantities do not have identical dimension?
a) Pressure and Young's modules
b) Planck's constant and Angular momentum
c) Impulse and moment of force
d) Force and rate of change of linear momentum
Explanation:
Impulse and moment of force.
97.If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same:
a) Velocity
b) Momentum
c) Acceleration
d) Kinetic energy
Explanation: Since the Force and the duration of time for which it acted are same, the product of force and time will be the same for both. Since Force×time gives change in momentum of a body, and they had 0 momentum initially, their final momenta will be same.
98. Pick out the scalar quantity
a) Force
b) Pressure
c) Velocity
d) Acceleration
Explanation: Pressure is a scalar quantity.
99. Rectifiers are used to convert:
a) Direct current to Alternating current
b) Alternating current to Direct current
c) High voltage to low voltage
d) Low voltage to high voltage
Explanation: A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification, since it "straightens" the direction of current.
100. Out of the following, which is not emitted by radioactive substance?
a) Electrons
b) Electromagnetic radiations
c) Alpha particles
d) Neutrons
Explanation: Out of the following neutrons is not emitted by radioactive substance.