Physics Top MCQs – 9

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
Answer: Option C

Radio telescopes are better than optical telescopes because
(A) They can detect faint galaxies which no optical telescope can
(B) They can work even in cloudy conditions
(C) They can work during the day and night
(D) All of the above
Answer: Option D

Mercury is commonly used as a thermometric fluid rather than water because
(A) Specific heat of mercury is less than water
(B) Specific heat of mercury is more than water
(C) Mercury has greater visibility than water
(D) Density of mercury is more than the water
Answer: Option C

When light passes from air into glass it experiences change of
(A) Frequency and wavelength
(B) Frequency and speed
(C) Wavelength and speed
(D) Frequency, wavelength and speed
Answer: Option C

When a given amount of air is cooled
(A) The amount of moisture it can hold decreases
(B) Its absolute humidity decreases
(C) Its relative humidity remains constant
(D) Its absolute humidity increases
Answer: Option A

When cream is separated from milk
(A) The density of milk increases
(B) The density of milk decreases
(C) The density of milk remains unchanged
(D) It becomes more viscous
Answer: Option A

Weight of an object put in a satellite orbiting in space around the earth is
(A) The same as on the earth
(B) Slightly more than that on the earth
(C) Less than that on the earth
(D) Reduced to zero
Answer: Option D

The three abundant elements in the earth’s crust are aluminium, oxygen and silicon. The correct order of their abundance is
(A) Oxygen, aluminium, silicon
(B) Aluminium, silicon, oxygen
(C) Oxygen, silicon, aluminium
(D) Silicon, oxygen, aluminium
Answer: Option C

Out of the following, which is not emitted by radioactive substance?
(A) Electrons
(B) Electromagnetic radiations
(C) Alpha particles
(D) Neutrons
Answer: Option D

Materials for rain-proof coats and tents owe their water-proof properties to
(A) Surface tension
(B) Viscosity
(C) Specific gravity
(D) Elasticity
Answer: Option A