300 Physics MCQ for Competitive Exams
Science is a complex and challenging subject, as it involves so many principles and concepts that are difficult to memorize. Those student who opt for science have to face many challenges and work hard to get good marks in the exam. In this Article, students will learn about Physics MCQ for Competitive Exams. The best solution of the problem is to practice as many Important Questions as possible to clear the doubts. These MCQs will help in all type exam related to Physics like TGT, PGT, KVS, and NEET etc.
Q1. For which Diode is used?
(a) modulation
(b) oscillation
(c) amplification
(d) purification
Answer : (d)
Q2. Who among the following developed the technology of underground nuclear explosion?
(a) Dr. Horn J. Bhabha
(b) Dr. Vikram Sarabhai
(c) Dr. Raja Ramanna
(d) Dr. P. K. Iyengar
Answer : (a)
Q3. Which among the following types of coal produces most heat per unit?
(a) Coal
(b) Lignite
(c) Anthracite
(d) Pit
Answer : (c)
Q4. Which among the following waves is used for communication by artificial satellites?
(a) Microwaves
(b) Radio waves
(c) A. M.
(d) Frequency of 101 series
Answer : (a)
Q5. What is found in frequency modulation?
(a) Fixed frequency
(b) Fixed dimension
(c) Change In frequency and dimension
(d) Change in dimension only
Answer : (a)
Q6. When the speed of car is doubled then what will be the braking force of the car to stop it in the same distance?
(a) four times
(b) two times
(c) half
(d) one fourth
Answer : (a)
Q7. The dimension of which of the following is the same as that of impulse?
(a) Volume
(b) Momentum
(c) Torque
(d) Change in the rate of momentum
Answer : (b)
Q8. Which among the following is the fundamental quantity?
(a) Volume
(b) Time
(c) Velocity
(d) Force
Answer : (b)
Q9. If the diameter of a capillary is doubled then the rise of water in it will be
(a) two times
(b) half
(c) four times
(d) no change
Answer : (b)
Q10. Why the needle of iron swims on Water surface when it is kept gently?
(a) It will remain under the water when it will displace more water than its weight
(b) the density of needle is less than that of water
(c) due to surface tension
(d) due to its shape
Answer : (c)
Q11. The mass of a star is two times the mass of the Sun. How it will come to an end?
(a) Neutron Star
(b) Black hole
(c) White Dwarf
(d) Red Giant
Answer : (a)
Q12. Rain drops fall from great height. Which among the following statements is true regarding it?
(a) they fall with that ultimate velocity which are different for different droplets
(b) they fall with same ultimate velocity
(c) their velocity increases and they fall With different velocity on the earth
(d) their velocity increases and they fall with same velocity of the earth
Answer : (a)
Q13. On which of the following techniques photo state machine works?
(a) Magnetic Imager Making
(b) Thermal Image Making
(c) Electrostatic Image Making
(d) Electromagnetic Image Making
Answer : (c)
Q14. One Kilowatt hour is equal
(a) 6 Mega Joule
(b) 8 Mega Joule
(c) 2 Mega Joule
(d) 0 Mega Joule
Answer : (a)
Q15. What is the minimum escape velocity of rocket to be launched into space?
(a) 5 Km Sec.
(b) 6 Km Sec.
(c) 11 Km. Sec.
(d) 15 Km. Sec.
Answer : (c)
Q16. Which of the following statements is true when we see rainbow?
(a) We face sun and raindrops
(b) The Sun remains behind us and we face raindrops
(c) In light rainfall we face Sun
(d) The sky remains clear and the sun is at lower position in the sky
Answer : (b)
Q17. The splitting of different colours of light in a prism is:
(a) Reflection of light
(b) Dispersion of light
(c) Diffraction of light
(d) Refraction of light
Answer : (b)
Q18. A boat will submerge when it displaces water equal to its own
(a) volume
(b) weight
(c) surface area
(d) density
Answer : (b)
Q19. Two waves each of amplitude 5 mm and frequency 10 Hz are travelling in opposite direction with a speed of 20 mms. The distance in mm between adjacent nodes is:
(a) 0
(b) 2
(c) 5
(d) 1
Answer : (a)
Q20. The snow on the mountains does NOT melt all at once when it is heated by the sun because:
(a) it becomes very hard
(b) it reflects most of the heat from the sun
(c) it has a low specific heat capacity
(d) it has a high latent heat of fusion
Answer : (b)
Q21. A person standing on a railway platform listens to the whistles of arriving and departing trains. The whistle heard is
(a) the same in both cases in all respects
(b) of higher intensity when train arrives
(c) of higher pitch when train arrives
(d) of higher pitch when train departs
Answer : (c)
Q22. Holography is a technique of
(a) recording a permanent sharp two dimensional black and white or multicolor photograph
(b) recording a permanent three dimensional multicolour photograph
(c) recording a permanent three dimensional black and white photograph
(d) recording a permanent three dimensional photograph of a given single colour or a multicolor
Answer : (d)
Q23. An ice block with a piece of lead embedded in it floats in water. If ice melts the water level
(a) Rises
(b) Falls
(c) Remains same
(d) Falls first and then rises
Answer : (b)
Q24. The velocity of heat radiation in vacuum is
(a) Equal to that of light
(b) Less than that of light
(c) Greater than that of light
(d) Equal to that of sound
Answer : (a)
Q25. The plastic material commonly used for making gear wheels is
(a) Polyesters
(b) Nylons
(c) Bakelite
(d) Polystyrene
Answer : (b)
Q26. Which of the following is used in oven?
(a) X-rays
(b) UV rays
(c) Microwaves
(d) Radio waves
Answer : (c)
Q27. When heated from 0° to 10°C 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
Answer : (d)
Q28. Energy is continuously created in the sun due to:
(a) nuclear fusion
(b) nuclear fission
(c) radioactivity
(d) artificial radioactivity
Answer : (a)
Q29. Coolis tube is used to produce
(a) Radio waves
(b) Microwaves
(c) X-rays
(d) Gama rays
Answer : (c)
Q30. Which of the following is used for regulated electric supply?
(a) Zener diode
(b) Junction diode
(c) Gun diode
(d) Tunnel diode
Answer : (a)
Q31. Gamma rays can cause
(a) gene mutation
(b) sneezing
(c) burning
(d) fever
Answer : (a)
Q32. The substance which conducts current in the solid state is
(a) diamond
(b) graphite
(c) iodine
(d) sodium chloride
Answer : (b)
Q33. Which set of conditions represents the easiest way to liquify a gas?
(a) Low temperature and high pressure
(b) High temperature and low pressure
(c) Low temperature and low pressure
(d) High temperature and high pressure
Answer : (a)
Q34. What is colour of light related to?
(a) Amplitude
(b) Frequency
(c) Quality
(d) Velocity
Answer : (a)
Q35. What principle law explains the working of the hydraulic brakes in automobiles?
(a) Bernoulli’s law
(b) Posieulles principle
(c) Pascal’s law
(d) Archimedes principle
Answer : (c)
Q36. The best conductor of heat among the following is
(a) alcohol
(b) mercury
(c) ether
(d) Water
Answer : (b)
Q37. What is viewed through an electron microscope?
(a) Electrons and other elementary particles
(b) Structure of bacteria and viruses
(c) Inside of human stomach
(d) Inside of the human eye
Answer : (b)
Q38. What apparatus is used to locate a submerged object?
(a) Radar
(b) Sonar
(c) Quasar
(d) Pulsar
Answer : (b)
Q39. Which combination of colour is the most convenient during day and night time?
(a) Orange and blue
(b) White and black
(c) Yellow and blue
(d) Red and green
Answer : (d)
Q40. The instrument that measures and records the relative humidity of air is
(a) Hydrometer
(b) Hygrometer
(c) Lactometer
(d) Barometer
Answer : (b)
Q41. The shape of our milky way galaxy is
(a) circular
(b) elliptical
(c) spiral
(d) None of the above
Answer : (c)
Q42. The different colours of different stars are due to the variation of
(a) temperature
(b) pressure
(c) density
(d) radiation from them
Answer : (a)
Q43. Wollen clothes keep the body warm because
(a) Wool increases the temperature of the body
(b) Wool is a bad conductor
(c) Wool absorbs radiant heat from outer objects
(d) Wool rejects heat from the outer objects
Answer : (b)
Q44. If the length of a simple pendulum is halved then its period of oscillation is
(a) doubled
(b) halved
(c) increased by a factor
(d) decreased by a factor
Answer : (d)
Q45. Mist is caused by
(a) dry ice
(b) ice at low temperature
(c) water vapour at low temperature
(d) carbon monoxide in solid form
Answer : (c)
Q46. While catching a ball a player pulls down his hands to lower the
(a) force
(b) momentum
(c) Impulse
(d) catching time
Answer : (b)
Q47. When a barometer reading suddenly recedes it indicates that climate
(a) will be very warm
(b) will be extremely stormy
(c) will remain cold
(d) incessant rain for at least 48 hours
Answer : (b)
Q48. A particle dropped from the top of a tower uniformly falls on ground at a distance which is equal to the height of tower. Which of the following paths will be traversed by the particle?
(a) Circle
(b) Parabolic
(c) Great circle
(d) Hyper parabolic
Answer : (b)
Q49. Electron microscope was invented by
(a) Knoll and Ruska
(b) Robert Koch
(c) Leeuwenhoek
(d) C.P. Swanson
Answer : (a)
Q50. When a bottle of scent is kept open in a comer of a room its odour is felt in all parts of the room. This is due to the phenomenon of:
(a) evaporation
(b) vaporization
(c) diffusion
(d) sublimation
Answer : (c)
Q51. Clear nights are colder than cloudy nights because of
(a) conduction
(b) condensation
(c) radiation
(d) insulation
Answer : (d)
Q52. A gas thermometer is more sensitive than a liquid thermometer because a gas:
(a) is lighter than liquid
(b) expands more than a liquid
(c) is easy to obtain
(d) does not change state easily
Answer : (d)
Q53. Which one of the following is used for sun glasses?
(a) Pyrex glass
(b) Flint glass
(c) Crooks glass
(d) Crystal glass
Answer : (c)
Q54. The speed of light with the rise in the temperature of the medium:
(a) Increases
(b) Decreases
(c) Remains unaltered
(d) Drops suddenly
Answer : (c)
Q55. When the barometer reading dips suddenly it is an indication of
(a) Hot weather
(b) Calm weather
(c) Storm
(d) Dry weather
Answer : (c)
Q56. Good conductor of electricity is
(a) dry air
(b) paper
(c) kerosene
(d) graphite
Answer : (d)
Q57. Heat from the Sun reaches the Earth by
(a) Reflection
(b) Conduction
(c) Radiation
(d) Convection
Answer : (c)
Q58. In which of the following cases kinetic energy is being used in performing work?
(a) Paddling the bicycle to cover a distance
(b) Driving a car to cover a distance
(c) Wind mill grinding wheat grain
(d) Rowing a boat in the lake
Answer : (b)
Q59. If the velocity time graph of a particle is represented by y = mt + c then the particle is moving with
(a) constant speed
(b) constant velocity
(c) constant acceleration
(d) varying acceleration
Answer : (c)
Q60. Which of the following occurred first?
(a) Albert Einstein propounded the General Theory of Relativity
(b) Max Planck unveiled the Quantum Theory
(c) Guglielmo Marconi sent out the first wireless signals
(d) Wright Brothers successfully flew an aircraft
Answer : (c)
Q61. A passenger standing In a bus is thrown outward when the bus takes a sudden turn happens due to
(a) Outward pull on him
(b) Inertia of motion
(c) Change in momentum
(d) Change in acceleration
Answer : (b)
Q62. When pressure is increased the melting point of ice
(a) increases
(b) does not change
(c) decreases
(d) depends on the impurities in the ice
Answer : (c)
Q63. Longitudinal waves cannot travel through
(a) Vacuum
(b) Solid
(c) Liquid
(d) Gas
Answer : (a)
Q64. Electrostatic precipitator is used to control the pollution of
(a) air
(b) water
(c) noise
(d) thermal
Answer : (a)
Q65. The sky appears blue because of
(a) Atmospheric water vapour
(b) Scattering of light
(c) Reflection on sea water
(d) Emission of blue wavelength by the sun
Answer : (b)
Q66. Dynamo is a device for converting
(a) Heat energy into electrical energy
(b) Mechanical energy into electrical energy
(c) Magnetic energy into electrical energy
(d) Chemical energy Into electrical energy
Answer : (b)
Q67. Oil rises up the wick in a lamp because
(a) Oil is very light
(b) Of the diffusion of oil through the wick
(c) Of the surface tension phenomenon
(d) Of the capillary action phenomenon
Answer : (d)
Q68. In the atmosphere ultraviolet rays are absorbed by
(a) Oxygen
(b) Nitrogen
(c) Ozone
(d) Helium
Answer : (a)
Q69. An electron microscope gives higher magnification than an optical microscope because:
(a) it uses more powerful lenses
(b) the velocity of electron is smaller than that of visible light
(c) the electrons have more energy than the light particles
(d) the wavelength of elections is smaller as compared to the wavelength of visible light
Answer : (d)
Q70. For a body moving with no uniform velocity and uniform acceleration
(a)(X) Displacement Time graph is linear.
(b) Displacement Time graphic is nonlinear
(c)Velocity Time graph is nonlinear
(d)Velocity Time graph is linear
Answer : (b)
Q71. Lamberts law is related to
(a) Reflection
(b) Refraction
(c) Interference
(d) illumination
Answer : (d)
Q72. Which of the following laws validates the statement that matter can neither be created nor destroyed?
(a) Law of conservation of energy
(b) Le Chateliers Principle
(c) Law of conservation of mass
(d) Law of osmosis
Answer : (c)
Q73. Decibel is the unit used for
(a) Speed of light
(b) Intensify of heat
(c) Intensity of sound
(d) Radio wave frequency
Answer : (c)
Q74. The term Isoneph indicates the lines of equal
(a) cloudiness
(b) salinity
(c) rainfall
(d) pressure
Answer : (a)
Q75. The atmospheric layer reflecting radio waves is called
(a) Ozonosphere
(b) Ionosphere
(c) Stratosphere
(d) Mesosphere
Answer : (b)
Q76. Cryogenics is a science dealing with
(a) high temperatures
(b) low temperatures
(c) friction and wear
(d) growth of crystals
Answer : (b)
Q77. The mass energy relation is the outcome of
(a) quantum theory
(b) general theory of relativity
(c) field theory of energy
(d) special theory of relativity
Answer : (d)
Q78. Which of the following are used for accurately measuring very small time intervals?
(a) Pulsars
(b) Quartz clocks
(c) Atomic clocks
(d) White dwarfs
Answer : (c)
Q79. Danger signals are generally red as red light
(a) is least bright
(b) undergoes least deviation
(c) has lowest velocity
(d) gives comfort to eye
Answer : (b)
Q80. A simple microscope consists of
(a) a short focus convex lens
(b) a long focus convex lens
(c) a short focus concave lens
(d) a long focus concave lens
Answer : (a)
Q81. An oil drop spreads over water because
(a) oil Is lighter than water
(b) oil is more viscous
(c) oil does not mix with water
(d) surface tension of oil is much smaller than that of water
Answer : (d)
Q82. The device which convert AC to DC is:
(a) Oscillator
(b) Amplifier
(c) Rectifier
(d) None of these
Answer : (c)
Q83. Knot is a measure of
(a) The speed of ship
(b) The curvature of spherical objects
(c) Solar radiation
(d) Intensity of earthquake shock
Answer : (a)
Q84. When the main switch of the house is put off it disconnects the
(a) live wire only
(b) live wire and the earth wire
(c) live wire and the neutral wire
(d) earth wire and the neutral wire
Answer : (c)
Q85. Heat from the sun reaches earth by the process of
(a) Conduction
(b) Convection
(c) Radiation
(d) All of the above
Answer : (c)
Q86. Which of the following produces more severe bums?
(a) Boiling water
(b) Hot water
(c) Steam
(d) Melting iceberg
Answer : (c)
Q87. The sudden fall of atmospheric pressure indicates
(a) fair weather
(b) storm
(c) rain
(d) cold weather
Answer : (b)
Q88. Magnetism in materials is due to
(a) electrons at rest
(b) circular motion of electrons
(c) protons at rest
(d) all neutrons at rest
Answer : (b)
Q89. Short sight in human eye can be corrected by using proper
(a) convex lens
(b) concave lens
(c) cylindrical lens
(d) bifocal lens
Answer : (b)
Q90. What is the reason for twinkling of stars?
(a) Dispersion of light
(b) Total internal reflection
(c) Atmospheric reflection
(d) Atmospheric refraction
Answer : (d)
Q91. The instrument for measuring intensity of earthquakes is called
(a) Ideograph
(b) Pantograph
(c) Ergo graph
(d) Seismograph
Answer : (d)
Q92. A multimeter is used to measure
(a) current
(b) voltage
(c) resistance
(d) All of the above
Answer : (d)
Q93. Which of the following is used to split white light Into different colours?
(a) Glass slab
(b) Convex lens
(c) Concave lens
(d) Prism
Answer : (d)
Q94. Nuclear reactors used to produce electricity are based on
(a) nuclear fission
(b) nuclear fusion
(c) Cold Fusion
(d) superconductivity
Answer : (a)
Q95. Which one of the following instruments is used to study dispersion of light?
(a) Microscope
(b) Telescope
(c) Spectrometer
(d) Photometer
Answer : (c)
Q96. A fountain pen Works on the principle of
(a) flow of liquids from higher to lower potential
(b) capillary action
(c) Bernoullis principle
(d) Viscosity of liquids
Answer : (b)
Q97. Pycnometer is an instrument used to measure the
(a) density
(b) intensity of solar radiation
(c) intensity of earthquake
(d) high temperatures
Answer : (a)
Q98. Fibre optics work on the principle of
(a)scattering of light
(b)total internal absorption
(c)total internal reflection
(d)optical rotation
Answer : (c)
Q99. A decibel is
(a) a musical instrument
(b) the wavelength of noise
(c) a musical note
(d) a measure of sound level
Answer : (d)
Q100. Remote sensing device has an Inbuilt source of
(a) X-ray
(b) gray
(c) ultraviolet ray
(d) infrared ray
Answer : (d)
Q101. A device used for converting A.C. into D.C. is called
(a) transformer
(b) rectifier
(c) induction coil
(d) dynamo
Answer : (b)
Q102. Energy of Ultraviolet rays is great than
(a) Infrared rays
(b) Gamma rays
(c) X-rays
(d) Cosmic rays
Answer : (a)
Q103. The instrument used to measure the speed of the wind is
(a) Altimeter
(b) Anemometer
(c) Chronometer
(d) Dosimeter
Answer : (b)
Q104. Who defined the law of gravitation?
(a) Newton
(b) Archimedes
(c) Galileo
(d) Faraday
Answer : (a)
Q105. The metal used to make lightning conductors is
(a) Iron
(b) Aluminum
(c) Copper
(d) Zinc
Answer : (c)
Q106. A hydrogen balloon floats up because of
(a) air pressure decreases with decrease in height
(b) air pressure decreases with decrease in weight
(c) weight of the balloon is less than the weight of air displaced by it
(d) the pressure inside the balloon is more than the pressure outside it
Answer : (c)
Q107. Which one of the following lenses should be used to correct the defect of astigmatism?
(a) Cylindrical lens
(b) Concave lens
(c) Convex lens
(d) Bifocal lens
Answer : (a)
Q108. In a Laser (say neon laser) all the atoms emit the light waves of
(a) Same frequency
(b) Same amplitude
(c) Same phase
(d) All of the above
Answer : (d)
Q109. Which of the following has got more heat capacity?
(a) Iron piece
(b) Water
(c) Gold piece
(d) Benzene
Answer : (b)
Q110. If the temperature of a place Increases suddenly the relative humidity
(a) Increases
(b) Decreases
(c) Remains constant
(d) Fluctuates
Answer : (b)
Q111. What Is the full form of AM regarding radio broadcasting?
(a) Amplitude Movement
(b) Anywhere Movement
(c) Amplitude Matching
(d) Amplitude Modulation
Answer : (d)
Q112. Which colour is the complementary colour of yellow?
(a) Blue
(b) Green
(c) Orange
(d) Red
Answer : (a)
Q113. During washing of clothes we use indigo due to its
(a) better cleaning action
(b) proper pig mental composition
(c) high glorious nature
(d) very low cost
Answer : (b)
Q114. The energy stored in a watch spring is
(a) kinetic energy
(b) potential energy
(c) heat energy
(d) chemical energy
Answer : (b)
Q115. The sensation of weightlessness in a spacecraft in an orbit is due to the
(a) absence of gravity outside
(b) acceleration in the orbit which is equal to the acceleration due to gravity outside
(c) presence of gravity outside but not inside the spacecraft
(d) fact that spacecraft in the orbit has ho energy
Answer : (b)
Q116. Therm is the unit of
(a) power
(b) heat
(c) light
(d) distance
Answer : ()
Q117. Newtons first law of motion gives the concept of
(a)energy
(b)work
(c)momentum
(d)inertia
Answer : (d)
Q118. A pond of water appears less deep due to
(a) reflection
(b) diffraction
(c) refraction
(d) polarization
Answer : (c)
Q119. The oldest type of energy known to man is
(a) wind power
(b) solar power
(c) tidal energy
(d) geothermal energy
Answer : (d)
Q120. Energy that is produced commercially from coal is called
(a) Light energy
(b) Kinetic energy
(c) Thermal energy
(d) Potential energy
Answer : (c)
Q121. We always see the same face of the moon because
(a) it is smaller than the earth
(b) it revolves on its axis in a direction opposite to that of the earth
(c) it takes equal time for revolution around the earth and rotation on its own axis
(d) it rotates at the same speed as the earth around the sun
Answer : (c)
Q122. Water pipes in hilly areas often burst on a cold frosty night because
(a) the material of which pipes are made contracts due to cold and so breaks
(b) water in the pipes freezes and on freezing water expands so pipes break
(c) frost makes the pipes rusty so they break
(d) None of these
Answer : (b)
Q123. A parachute descends slowly whereas a stone dropped from the same Height falls rapidly because
(a) stone is heavier than parachute
(b) special mechanisms are present in parachute
(c) a parachute has a larger surface area and air resistance is more
(d) None of these
Answer : (c)
Q124. Which of the following instruments is used to measure humility?
(a) Kata Thermometer
(b) Anemometer
(c) Sling Psychomotor
(d) Clinical Thermometer
Answer : (c)
Q125. The type of mirrors used in the headlamp of cars is
(a) parabolic concave
(b) plane
(c) spherical convex
(d) cylindrical concave
Answer : (a)
Q126. The reason for a swimming pool to appear less deep than the actual depth is
(a) refraction
(b) light scattering
(c) reflection
(d) interference
Answer : (a)
Q127. Alternating current is converted into direct current by a
(a) transformer
(b) dynamo
(c) oscillator
(d) rectifier
Answer : (d)
Q128. Which of the following is most elastic?
(a) Rubber
(b) Wet clay
(c) Steel
(d) Plastic
Answer : (c)
Q129. When a person walking in bright Sunlight enters a dark room he is not able to see clearly for a little while because
(a) the eye muscles cannot immediately adjust the focal length of the eye lens.
(b) the retina retains the bright images for sometime and becomes momentarily insensitive.
(c) the iris is unable to contract the pupil immediately
(d) the iris is unable to dilate the pupil immediately
Answer : (d)
Q130. The swing of a spinning cricket ball in air can be explained on the basis of
(a) Sudden change in wind direction.
(b) Buoyancy of air.
(c) Turbulence caused by wind.
(d) Bernoulli’s theorem.
Answer : (c)
Q131. Why two thin shirts can keep us warmer than a single thick shirt in winter?
(a) Two thin shirts become thicker so prevent transmission of heat
(b) Air layer between two shirts works as good conductor
(c) Air layer between two shirts behaves like insulating media
(d) No radiation of heat takes place
Answer : (c)
Q132. Which layer of the earth’s atmosphere reflect back the radio waves to the earth’s surface?
(a) ionosphere
(b) stratosphere
(c) mesosphere
(d) exosphere
Answer : (a)
Q133. Sound cannot pass through
(a) water
(b) steel
(c) air
(d) vacuum
Answer : (d)
Q134. In a photocell light energy is converted into
(a) potential energy
(b) chemical energy
(c) heat energy
(d) electrical energy
Answer : (d)
Q135. A storm is predicted if atmospheric pressure
(a) rises suddenly
(b) rises gradually
(c) falls suddenly
(d) falls gradually
Answer : (c)
Q136. What should a person on a freely rotating turn table do to decrease his (angular) speed?
(a) Bring his hands together
(b) Raise his hands up
(c) Spread his hands outwards
(d) Sit down with raised hands
Answer : (c)
Q137. Which of the following celestial bodies contains abundant quantities of helium3 a potential source of energy?
(a) Earth
(b) Moon
(c) Venus
(d) Saturn
Answer : (b)
Q138. Smog is a combination of
(a) Air and water vapours
(b) Water and smoke
(c) Fire and water
(d) smoke and fog
Answer : (d)
Q139. Which of the following circuit elements is used to block DC in an electronic circuit?
(a) Resistances
(b) Capacitance
(c) Inductance
(d) Diode
Answer : (b)
Q140. Spectacles used for viewing 3D films have
(a) Bifocal lens
(b) Convex lens
(c) Concave lens
(d) Polaroid’s
Answer : (d)
Q141. A boy sitting in an open car moving with the constant speed throws a ball straight up into the air. The ball falls
(a) behind him
(b) in front of him
(c) into his hand
(d) by his side
Answer : (a)
Q142. The process involved in making soap is
(a) saponification
(b) hydrolysis
(c) condensation
(d) polymerisation
Answer : (a)
Q143. A kilowatt-hour is unit of
(a) Energy
(b) Power
(c) Electric charge
(d) Electric current
Answer : (a)
Q144. Ventilators are provided near the ceiling of the room because
(a) the exhaled warmer air rises up and goes out
(b) these provide cross ventilation in the room
(c) these provide some sunlight in the room
(d) these do not look nice in the lower part
Answer : (a)
Q145. The hair of shaving brush clings together when removed from water due to
(a) Surface tension
(b) Viscosity
(c) Elasticity
(d) Friction
Answer : (a)
Q146. In severe winter in cold countries water pipes burst because
(a) water expands on freezing
(b) contraction of water pipes
(c) high atmospheric pressure
(d) combined effect of all the above three.
Answer : (a)
Q147. In the process of magnetization of a bar
(a) The entire bulk of the bar gets magnetised
(b) Only the surface of the bar gets magnetised
(c) Only the ends of the bar get magnetised
(d) Only some parts of the outer layers of the bar get magnetized
Answer : (a)
Q148. A falling drop of rain water acquires the spherical shape due to
(a) Viscosity
(b) Surface Tension
(c) Atmospheric pressure
(d) Gravitational force
Answer : (b)
Q149. The weakest of all fundamental forces is
(a) Gravitational force
(b) Electrostatic force
(c) Magnetic force
(d) Nuclear force
Answer : (a)
Q150. Velocity of sound in air does not change with the change of
(a) Temperature of air
(b) Pressure of air
(c) Moisture content in air
(d) Wind in the direction of propagation of sound
Answer : (b)
Q151. The density of gas is maximum at
(a) Low temperature low pressure
(b) Low temperature high pressure
(c) High temperature low pressure
(d) High temperature high pressure
Answer : (b)
Q152. Why is it difficult to breathe at higher altitudes?
(a) Due to low air pressure
(b) Due to low temperature
(c) Due to ozone
(d) Due to high humidity
Answer : (a)
Q153. The strongest force in nature is
(a) electrical force
(b) gravitational force
(c) nuclear force
(d) magnetic force
Answer : (c)
Q154. According to the theory of relativity which of the following alt ways remains constant?
(a) Length of an object
(b) Time
(c) Space
(d) Velocity of light
Answer : (d)
Q155. The spoon dropped by an astronaut in a satellite will
(a) fall to the floor
(b) remain stationary
(c) continue to follow the motion of the satellite
(d) move tangentially away
Answer : (c)
Q156. Pipelines in cold countries often burst in winter because
(a) water freezes and expands in its volume
(b) temperature of ice is less than that of water
(c) pipelines contract in their volume
(d) pipelines expand due to freezing
Answer : (a)
Q157. When a body is taken from earth to moon
(a) mass changes but weight remains same
(b) weight changes but mass remains same
(c) both weight and mass change
(d) both weight and mass remain same
Answer : (b)
Q158. A mirage occurs because of
(a) reflection by hot ground
(b) total internal reflection by layers of air
(c) interference of light
(d) diffraction of light
Answer : (b)
Q159. Atomic power plant work son the principle of
(a) fission
(b) fusion
(c) thermal combustion
(d) combined effect of all the above three
Answer : (a)
Q160. Bolometer is used to measure
(a) Frequency
(b) Temperature
(c) Velocity
(d) Wavelength
Answer : (b)
Q161. ATM stands for
(a) Automatic Teller Machine
(b) Automated Teller Machine
(c) Automatic Tally Machine
(d) Automated Tally Mechanism
Answer : (a)
Q162. A person is hurt on kicking a stone due to
(a) Inertia
(b) Velocity
(c) Reaction
(d) Momentum
Answer : (c)
Q163. The fuse in pure domestic electric circuit melts when there is a high rise in
(a) Inductance
(b) Current
(c) Resistance
(d) Capacitance
Answer : (b)
Q164. Which of the following is an example for cantilever beam?
(a) Diving board
(b) Bridge
(c) Seesaw
(d) Common balance
Answer : (b)
Q165. UK It is difficult to cook rice
(a) at the top of a mountain
(b) at the sea level
(c) under a mine
(d) same anywhere
Answer : (a)
Q166. A dynamo is a device which
(a) creates mechanical energy
(b) creates electrical energy
(c)converts mechanical energy into electrical energy
(d) converts electrical energy into mechanical energy
Answer : (c)
Q167. A soap bubble shows colours when illuminated with white light. This is due to
(a) Diffraction
(b) Polarization
(c) Interference
(d) Reflection
Answer : (c)
Q168. The Instrument used to see the distant objects on the Earth is
(a) Terrestrial telescope
(b) Astronomical telescope
(c) Compound microscope
(d) Simple microscope
Answer : (a)
Q169. Global warming is expected to result in
(a) increase in level of sea
(b) change in crop pattern
(c) change in coast line
(d) All of the above
Answer : (d)
Q170. Which of the following liquids has the least density?
(a) Fresh water
(b) Salt water
(c) Petrol
(d) Mercury
Answer : (c)
Q171. Which of the following principle is used to produce low temperatures?
(a) Superconductivity
(b) Joule Kelvin effect
(c) Thermoelectric effect
(d) Adiabatic demagnetization
Answer : (d)
Q172. A photoelectric cell converts
(a) mechanical energy to electric energy
(b) heat energy to mechanical energy
(c) light energy to chemical energy
(d) light energy to electrical energy
Answer : (d)
Q173. Two stones of different masses are dropped simultaneously from the top of a building
(a) Smaller stone reaches the ground earlier
(b) Larger stone reaches the ground earlier
(c) Both the stones reach the ground at the same time
(d) None of these
Answer : (c)
Q174. The device used to change the speed of an electric fan is
(a) Amplifier
(b) Regulator
(c) Switch
(d) Rectifier
Answer : (d)
Q175. Fog is an example of
(a) Gas dispersed in gas
(b) Liquid dispersed in gas
(c) Solid dispersed in gas
(d) Solid dispersed in liquid
Answer : (b)
Q176. A concave lens always forms an image which is
(a) real and erect
(b) virtual and erect
(c) real and inverted
(d) virtual and inverted
Answer : (b)
Q177. The modulus of rigidity Is the ratio of
(a) longitudinal stress to longitudinal strain
(b) Volume stress to volume strain
(c) shearing stress to shearing strain
(d) tensile stress to tensile strain
Answer : (c)
Q178. The propagation of sound waves in a gas involves
(a) adiabatic compression and rarefaction
(b) isothermal compression and rarefaction
(c) isochoric compression and rarefaction
(d) isobaric compression and rarefaction
Answer : (a)
Q179. Heat transfer horizontally within the atmosphere Is called
(a) Conduction
(b) Convection
(c) Absorption
(d) Advection
Answer : (d)
Q180. Noise is measured In
(a) Watt
(b) REM
(c) Centigrade
(d) Decibel
Answer : (d)
Q181. The bats can fly in the dark because
(a) they can see the objects in darkness
(b) they have weak legs and are likely to be attacked by predators
(c) they generate flashes of light
(d) they generate ultrasonic sound waves
Answer : (d)
Q182. What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
(a) All ice will melt
(b) All water will become ice
(c) No change will happen
(d) Only some ice will melt
Answer : (c)
Q183. Cupric point is the temperature at which
(a) Matter becomes radioactive
(b) A metal loses magnetic properties.
(c) A metal loses conductivity
(d) Transmutation of metal
Answer : (b)
Q184. Angle of friction and angle of repose are
(a) equal to each other
(b) not equal to each other
(c) proportional to each other
(d) None of the above
Answer : (a)
Q185. If a boy sitting in a train which is moving at a constant velocity throws a ball straight up into the air the ball will
(a) fall in front of him
(b) fall behind him
(c) fall into his hand
(d) None of the above
Answer : (c)
Q186. Intensity of gravitational field of earth is maximum at
(a) Poles
(b) Equator
(c) Centre of earth
(d) Surface
Answer : (a)
Q187. The spokes Used in the wheel of a bicycle increase its
(a) Moment of inertia
(b) Velocity
(c) Acceleration
(d) Momentum
Answer : (a)
Q188. A transformer works on the principle of
(a) Self induction
(b) Mutual induction
(c) Generator
(d) Inverter
Answer : (b)
Q189. The sky appears blue because
(a) all colours interfere to produce blue
(b) in white light the blue component dominates
(c) the atmosphere scatters blue colour more than the others
(d) it is actually blue
Answer : (c)
Q190. When a ship enters the sea from a river
(a) it rises a little
(b) it sinks a little
(c) it remains at the same level
(d) it rises or sinks depending on the material it is made of
Answer : (a)
Q191. Two stones of unequal masses are thrown vertically up with the same velocity. Which of the following will happen?
(a) The heavier mass will reach greater height
(b) The lighter mass will reach greater height
(c) Both will reach the same height
(d) Any of them may reach great height
Answer : (c)
Q192. The unit of electrical power is
(a) Bolt
(b) Watt
(c) Kilowatt hour
(d) Ampere
Answer : (a)
Q193. The scientist who first sent electromagnetic waves to distant places is
(a) James Clerk Maxwell
(b) Heinrich Hertz
(c) Thomas Alva Edison
(d) John Logie Baird
Answer : (c)
Q194. The centre of gravity of a sprinter during the race lies
(a) ahead of his feet
(b) behind his feet
(c) at the centre of the body
(d) to the left side of the body
Answer : (a)
Q195. Cloudy nights are warmer compared nights because clouds mainly
(a) absorb heat from the atmosphere send it towards earth
(b) prevent cold waves from the sky descending on earth
(c) reflect back the heat given by earth
(d) produce heat and radiate toward earth
Answer : (c)
Q196. A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole?
(a) Increase
(b) Decrease
(c) Remain constant
(d) Will increase first and then decrease
Answer : (a)
Q197. The period of revolution of a geo stationary satellite is
(a) 365 days
(b) 30 days
(c) 24 hours
(d) changing continuously
Answer : (c)
Q198. 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?
(a) They must have the same volume
(b) They must have the same density
(c) They must have the same mass
(d) They must be dropped in vacuum
Answer : (d)
Q199. The frequency of ultrasound wave is typically
(a) Above 20 kHz
(b) Above 20000 kHz
(c) Below 20 kHz
(d) Below 02 kHz
Answer : (c)
Q200. Which type of reaction produces the most harmful radiation?
(a) Fusion reaction
(b) Fission reaction
(c) Chemical reaction
(d) Photo Chemical reaction
Answer : (b)
Q201. Optical fibers are based on the phenomenon of
(a) Interference
(b) Dispersion
(c) Diffraction
(d) Total Internal Reflection
Answer : (d)
Q202. Mirage is an example of
(a) refraction of light only
(b) total internal reflection of light only
(c) refraction and total internal reflection of light
(d) dispersion of light only
Answer : (c)
Q203. The phenomenon of light associated with the appearance of blue colour of the sky is
(a) Interference
(b) Reflection
(c) Refraction
(d) Scattering
Answer : (d)
Q204. Lens is made up of
(a) Pyrex glass
(b) Flint glass
(c) Ordinary glass
(d) Cobalt glass
Answer : (b)
Q205. The time period of a pendulum when taken to the Moon would
(a) remain the same
(b) decrease
(c) become zero
(d) increase
Answer : (d)
Q206. The atmospheric air is held to the Earth by:
(a) gravity
(b) winds
(c) clouds
(d) rotation of the Earth
Answer : (a)
Q207. The function of ball bearings in a wheel is:
(a) to increase friction
(b) to convert kinetic friction into rolling friction
(c) to convert static friction into kinetic friction
(d) just for convenience
Answer : (b)
Q208. SHOCK ABSORBERS are usually made of steel because:
(a) is not brittle
(b) has lower elasticity
(c) has higher elasticity
(d) has no ductile property
Answer : (c)
Q209. Among the following materials sound travels fastest in
(a) Steel
(b) Air
(c) Vacuum
(d) Water
Answer : (a)
Q210. The time period of a seconds pendulum Is
(a) 1 second
(b) 2 seconds
(c) 5second
(d) 15 seconds
Answer : (b)
Q211. Lakes freeze in cold countries in winter leaving the water underneath at
(a) 0°C
(b) 0°F
(c) 4°C
(d) 4°F
Answer : (c)
Q212. Which one of the following determines the sharpness of image in a camera?
(a) The aperture
(b) The exposure time
(c) The focal length of the lens
(d) Size of the camera
Answer : (a)
Q213. In MRI machine which one Of the following is used?
(a) Sound wave
(b) X-ray
(c) Ultrasound wave
(d) Magnetic wave
Answer : (d)
Q214. For a person having hyper metropia the near point is
(a) greater than 25 cm
(b) greater than 50 cm
(c) less than 25 cm
(d) infinity
Answer : (a)
Q215. Amount of water vapour in the atmosphere is measured in terms of
(a) Humidity
(b) Droplets
(c) Smog
(d) All of the above
Answer : (a)
Q216. Name the process of production of energy in the Sun
(a) Nuclear fission
(b) Radioactivity
(c) Nuclear fusion
(d) Ionization
Answer : (c)
Q217. A spherical ball made of steel when dropped in mercury container will
(a) sink in mercury
(b) will be on the surface of mercury
(c) will be partly immersed mercury
(d) will dissolve in mercury
Answer : (b)
Q218. The sound having a frequency of 20 hertz to 20000 hertz are known as
(a) Audible sounds
(b) Ultrasonic’s
(c) Infrasonic
(d) Mega sonics
Answer : (a)
Q219. Eclipses occur due to which optical phenomena?
(a) Reflection
(b) Refraction
(c) Rectilinear propagation
(d) Diffraction
Answer : (c)
Q220. Pure water is bad conductor of electricity because it is
(a) feebly ionized
(b) not volatile
(c) a very good solvent
(d) a non polar solvent
Answer : (a)
Q221. The filament of electric bulb is made up of :
(a) Copper
(b) Nichrome
(c) Lead
(d) Tungsten
Answer : (d)
Q222. When a vibrating tuning fork is placed on a table a loud sound is heard. This is due to :
(a) reflection
(b) refraction
(c) forced vibrations
(d) damped vibrations
Answer : (c)
Q223. 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 war ships the location of a harbor during night.
(d) guide and warn the ships corning from different directions in the ocean.
Answer : (d)
Q224. A piece of wood is held under water. The up thrust on it will be:
(a) equal to the weight of the wood
(b) less than weight of the wood
(c) more than weight of the wood
(d) Zero
Answer : (b)
Q225. Persistence of vision is the principle behind
(a)Camera
(b) Spectroscope
(c) Cinema
(d) Periscope
Answer : (c)
Q226. In a nuclear reactor one of the following is used as a fuel
(a) Coal
(b) Uranium
(c) Radium
(d) Diesel
Answer : (b)
Q227. The density of the liquid when heated
(a) decreases
(b) increases
(c) does not change
(d) may increase of decrease depending on pressure
Answer : (a)
Q228. The distance between node and adjacent antinodes is 30 cm. The wavelength is
(a) 30 cm.
(b) 90 cm
(c) 120 cm.
(d) 60 cm.
Answer : (d)
Q229. The nature of fuse wire is
(a) high resistance and low melting point.
(b) high resistance and high melting point.
(c) low resistance and high melting point.
(d) low resistance and low melting point.
Answer : (a)
Q230. In a railway track two rails rejoined 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 expansible in summer can be avoided.
Answer : (d)
Q231. Vehicle tyres are inflated properly
(a) to ensure smooth running.
(b) to allow the vehicle to take more load.
(c) to avoid skidding and to minimize friction
(d) to go fast and save fuel.
Answer : (c)
Q232. Refrigeration is a process which
(a) kills bacteria
(b) slows down the bacterial growth
(c) Inactivates the bacteria
(d) Plasmolyses the bacteria
Answer : (b)
Q233. 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
Answer : (b)
Q234. After long periods of use a grey spot develops on the inside of a bulb. This is because
(a) the tungsten filament evaporates and collects there
(b) the heat of the bulb scorches the glass at the top
(c) dust inside the bulb condenses on the top
(d) glass undergoes a change due to the heat
Answer : (c)
Q235. Should cars have bumpers that collapse under impact?
(a) Yes since the offending car should get damaged and pay for the mistake
(b) No since it would be very expensive to get the car repaired
(c) No since the colliding car would then ram into the occupants and kill them
(d) Yes since they help to absorb the impact of a collision and keep the occupants safe
Answer : (d)
Q236. Ice cubes are added to a glass of pure water and a glass of pure alcohol. The ice would be
(a) at a higher level in water
(b) at a higher level in alcohol
(c) at the same level in both
(d) floating in alcohol and sinking In water
Answer : (a)
Q237. A person wears spectacles with concave lenses. It means that normally (when not using glasses) the image of distant objects is focused in his eyes
(a) behind the retina
(b) in front of the retina
(c) on the retina
(d) on the blind spot
Answer : (b)
Q238. What is the principle of a Life Jacket?
(a) It provides oxygen to a drowning person
(b) It increases the volume of the person to keep him afloat
(c) It decreases the volume of the person to keep him afloat
(d) The person can sit on It like a raft
Answer : (b)
Q239. Myopia is the same as
(a) Near sightedness
(b) Astigmatism
(c) Presbyopia
(d) Long sightedness
Answer : (a)
Q240. Sun’s heat reaches us by
(a) Conduction
(b) Convection
(c) Radiation
(d) Reflection
Answer : (c)
Q241. A sphere rolls down on two inclined planes of different angles but same height it does so
(a) in the same time
(b) with the same speed
(c) in the same time with the same speed
(d) in the same time with the same kinetic energy
Answer : (b)
Q242. Which one of the following has the highest value of specific heat?
(a) Glass
(b) Copper
(c) Lead
(d) Water
Answer : (d)
Q243. A microscope used in pathological laboratories forms
(a) magnified virtual erect image
(b) diminished real and erect image
(c) magnified virtual and inverted image
(d) diminished virtual and erect image
Answer : (c)
Q244. The velocity of sound is more of
(a) water
(b) air
(c) steel
(d) wood
Answer : (c)
Q245. The magnifying power of an astronomical telescope can be decreased by
(a) decreasing the focal length of the eyepiece
(b) increasing the focal length of the eyepiece
(c) increasing the focal length of the objective
(d) None of these
Answer : (b)
Q246. Necessary element of change in solar energy to electric energy
(a) Beryllium
(b) Silicon
(c) Tantelum
(d) Pure Copper
Answer : (b)
Q247. Which of the following events occurred first ?
(a) Albert Einstein propounded the General Theory of Relativity
(b) Max Planck unveiled the Quantum Theory
(c) Marconi first transmitted a wireless signal
(d) Madame Marie Curie became the first woman Nobel Prizewinner
Answer : (b)
Q248. The audio signals of TV are
(a) Amplitude modulated
(b) Frequency modulated
(c) Unmodulated
(d) Velocity modulated
Answer : (b)
Q249. Woollen cloth protects the body from cold because
(a) it is a good conductor of heat
(b) it is a poor conductor of heat
(c) external heat rays enter into the body through the woolen cloth
(d) it reflects heat
Answer : (b)
Q250. The owl can see most clearly in total darkness because
(a) it has squint eyes
(b) it has large eyes with orbs directed forward giving it binocular sight
(c) it has light bulbs in its eyes provided by nature
(d) it produces infrasonic sounds
Answer : (b)
Q251. Damp clothes are dried in spin dryers by the action of
(a) centripetal forces
(b) centrifugal forces
(c) central forces
(d) non central forces
Answer : (b)
Q252. Tape recorder should not be kept near one of the following things:
(a) Clock
(b) Magnet
(c) Electrical switchboard
(d) Radio
Answer : (b)
Q253. When a person sitting on a swing stands up on the swing the frequency of oscillation
(a) decreases
(b) increases
(c) becomes infinite
(d) does not change
Answer : (b)
Q254. Night photography and photography In mist and fog are possible using
(a) ultraviolet radiation
(b) infrared radiation
(c) microwave radiation
(d) gamma radiation
Answer : (b)
Q255. It is easier to carry two buckets of water in one hand each than to can only one in one hand because
(a) weights of buckets are balanced
(b) centre of gravity falls within the body
(c) centre of gravity and centre of equilibrium fall within the feet
(d) resultant weight of buckets is zero
Answer : (c)
Q256. The surface tension of water on adding detergent to it
(a) increases
(b) decreases
(c) no change
(d) becomes zero
Answer : (b)
Q257. Which of the following is optical illusion?
(a) Rainbow
(b) Earthshine
(c) Halo
(d) Mirage
Answer : (d)
Q258. An athlete runs before long jump to get advantage on
(a) Inertia of motion
(b) Frictional force
(c) Moment of a force
(d) Principle of moments
Answer : (a)
Q259. In sunlight a rose appears red. In green light the same rose appears:
(a) red
(b) black
(c) green
(d) yellow
Answer : (b)
Q260. The sparkling of a diamond is due to
(a) total internal reflection of light
(b) interference of light
(c) polarisation of light
(d) refraction of light
Answer : (a)
Q261. If a copper wire Is increased to double its length Its resistance will become
(a) four times
(b) one fourth
(c) double
(d) hall
Answer : (c)
Q262. In a diesel engine the high temperature needed to ignite the fuel Is achieved by
(a) using heat from exhaust
(b) the battery
(c) compressing air in the cylinders
(d) an electrical spark
Answer : (c)
Q263. Waves that are required for long distance wireless communication are
(a) infrared fays
(b) Ultraviolet rays
(c) Radio waves
(d) Microwaves
Answer : (c)
Q264. Rise of oil a wick is due to
(a) density of the oil
(b) viscosity of the oil
(c) surface tension of the oil
(d) pressure of the oil
Answer : (c)
Q265. The radiation initially produced in fluorescent tube is
(a) infrared
(b) ultraviolet
(c) microwaves
(d) X-rays
Answer : (b)
Q266. The four stroke petrol engine Is based on
(a) Carnot cycle
(b) Otto cycle
(c) Diesel cycle
(d) Boyles cycle
Answer : (b)
Q267. It is dangerous to observe Solar eclipse with naked eyes because
(a) Infrared radiations from sun burn our retina
(b) Ultraviolet radiations from Sun bum our retina
(c) All radiations from sun initiate chemical reactions in eyes
(d) Cosmic rays reach eyes more during the eclipse
Answer : (b)
Q268. A bomb at rest explodes into a large number of tiny fragments. The total momentum of all the fragments
(a) is zero
(b) depends on the total mass of all the fragments
(c) depends on the speeds of various fragments
(d) is infinity
Answer : (a)
Q269. An optically plane surface reflects a beam of light
(a) as a parallel beam in one direction
(b) as diffused beams in all directions
(c) as parallel beams in all directions
(d) as a diffused beam in one direction
Answer : (a)
Q270. The slope of a velocity time graph represents
(a) acceleration
(b) displacement
(c) distance
(d) speed
Answer : (a)
Q271. The earth wire of a cable is connected to
(a) the outer metallic body of the appliance
(b) the fuse of the appliance
(c) the filament of the appliance
(d) short circuitry of the appliance
Answer : (b)
Q272. Water Is used in car radiator because of its
(a) low density
(b) easy availability
(c) high specific heat capacity
(d) low boiling point
Answer : (c)
Q273. How much mechanical work must be done to completely melt 1 gram of ice at 0°C?
(a) 2 J
(b) 80 J
(c) 336 J
(d) 2268 J
Answer : (b)
Q274. A bullet is fired from a rifle which recoils after firing. The ratio of kinetic energy of the rifle to that of the bullet is
(a) zero
(b) one
(c) less than one
(d) more than one
Answer : (a)
Q275. The layer of atmosphere used for radio wave transmission is
(a) chromospheres
(b) troposphere
(c) ionosphere
(d) stratosphere
Answer : (c)
Q276. Negative feedback in amplifiers
(a) increases bandwidth and decreases noise
(b) decreases bandwidth and decreases noise
(c) increases bandwidth and increases noise
(d) decreases bandwidth and increases noise
Answer : (a)
Q277. Water cannot be used to extinguish fire caused by electric current because
(a) it may cause electrocution
(b) it may cause hydrolysis
(c) it may cause electrolysis
(d) it may spoil the wiring
Answer : (a)
Q278. A periscope works on the principle of
(a) refraction
(b) total internal reflection
(c) diffraction
(d) reflection
Answer : (b)
Q279. A copper disc has a hole. If the disc is heated the size of the hole
(a) increases
(b) decreases
(c) No change
(d) first increases and than decreases
Answer : ()
Q280. A rearview mirror for driving is
(a) plain
(b) concave
(c) convex
(d) inverted
Answer : (c)
Q281. The Important unit of a microprocessor is
(a) ALU
(b) array of registers
(c) control unit
(d) All of the above
Answer : (d)
Q282. Which one of the following has the highest value of specific heat?
(a) Glass
(b) Copper
(c) Lead
(d) Water
Answer : (d)
Q283. The device used for locating submerged objects under sea is
(a) sonar
(b) radar
(c) laser
(d) maser
Answer : (a)
Q284. The metal whose electrical conductivity is more is
(a) copper
(b) aluminum
(c) silver
(d) lead
Answer : (c)
Q285. What happens to a liquid when the vapour pressure equals the atmospheric pressure?
(a) The liquid cools
(b) The liquid boils
(c) No change
(d) The liquid evaporates
Answer : (b)
Q286. In nuclear reactor heavy water is used as
(a) coolant
(b) fuel
(c) moderator
(d) atomic smasher
Answer : (c)
Q287. Water boils at a lower temperature on the hills because
(a) it is cold on the hills
(b) there is less carbon dioxide on the hills
(c) there is a decrease in air pressure on the hills
(d) There is less oxygen
Answer : (c)
Q288. Why do birds not have respiratory trouble at the time of flying at high altitude?
(a) Their lungs are very large
(b) They fly Inactively
(c) They have extra air sacs
(d) They use less oxygen
Answer : (c)
Q289. The temperature which has the same reading on both Fahrenheit and Celsius scales is
(a) 40°
(b) 40°
(c) 34°
(d) 140°
Answer : (b)
Q290. Kilowatt hour is the unit of
(a) Energy
(b) Power
(c) Force
(d) Momentum
Answer : (a)
Q291. The part of the eye having the larges refractive index is:
(a) cornea
(b) aqueous humor
(c) lens
(d) vitreous humor
Answer : (c)
Q292. Conversion of heat into electrical is achieved by using:
(a) Ammeter
(b) Hydrometer
(c) Voltmeter
(d) Therm-ocouple
Answer : (d)
Q293. Ball pen functions on the principle of
(a) Viscosity
(b) Boyle's Law
(c) Gravitational force
(d) surface tension
Answer : (d)
Q294. A man cannot see clearly beyond 10 meters. The disease he suffers from:
(a) Far sight
(b) Myopia
(c) Cataract
(d) Hyper-metropia
Answer : (b)
Q295. When milk is churned the cream separates from it due to:
(a) Frictional force
(b) Centrifugal force
(c) Gravitational force
(d) Viscous forces
Answer : (b)
Q296. Moving electric charge produces:
(a)magnetic field
(b)sound waves
(c)light rays
(d)heat waves
Answer : (a)
Q297. The S.I. Unit of electric charge is:
(a) ampere
(b) coulomb
(c) e.s.u
(d) Kelvin
Answer : (b)
Q298. Light beam which is highly directional is called:
(a) eraser
(b) grazer
(c) maser
(d) laser
Answer : (d)
Q299. Permissible noise level at Residential area during night time Is:
(a) 45 dB (A)
(b) 55 dB(A)
(c) 75 dB(A)
(d) 80 dB(A)
Answer : (a)
Q300. Energy in reflected light:
(a) does not depends on the angle of incidence
(b) increases with the increase in angle
(c) decreases with the increase in angle of incidence
(d) becomes maximum for angle of incidence equal to 45°
Answer : (b)