Practice MCQ Questions and answers on Physics-GK

11

Stars appears to move from east to west because

A) All stars move from east to west B) The earth rotates from west to east C) The earth rotates from east to west D) The background of the stars moves from west to east

Discuss

Answer & Solution

Answer: Option B

Solution:

The earth rotates from west to east.

12

Pa(Pascal) is the unit for

A) Thrust B) Pressure C) Frequency D) Conductivity

Discuss

Answer & Solution

Answer: Option B

Solution:

Pa(Pascal) is the unit for pressure.

13

Planets do not twinkle because

A) They emit light of a constant intensity B) Their distance from the earth does not change with time C) They are very far away from the earth resulting in decrease in intensity of light D) They are nearer to earth and hence we receive a greater amount of light.

Discuss

Answer & Solution

Answer: Option D

Solution:

They are nearer to earth and hence we receive a greater amount of light.

14

Metals are good conductors of electricity because:

A) They contain free electrons. B) The atoms are lightly packed. C) They have high melting point. D) All of the above.

Discuss

Answer & Solution

Answer: Option A

Solution:

Metals are good conductors of electricity because they contain free electrons.

15

Let a thin capillary tube be replaced with another tube of insufficient length then, we find water

A) will overflow B) will not rise C) depressed D) change its meniscus

Discuss

Answer & Solution

Answer: Option B

Solution:

When length of capillary tube is insufficient then we would observe no rise on level of water because their will be no air pressure created enough to rise the water level.

16

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

Discuss

Answer & Solution

Answer: Option C

Solution:

Impulse and moment of force.

17

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

Discuss

Answer & Solution

Answer: Option B

Solution:

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.

18

Pick out the scalar quantity

A) Force B) Pressure C) Velocity D) Acceleration

Discuss

Answer & Solution

Answer: Option B

Solution:

Pressure is a scalar quantity.

19

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

Discuss

Answer & Solution

Answer: Option B

Solution:

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.

20

Out of the following, which is not emitted by radioactive substance?

A) Electrons B) Electromagnetic radiations C) Alpha particles D) Neutrons

Discuss

Answer & Solution

Answer: Option D

Solution:

Out of the following neutrons is not emitted by radioactive substance.