Practice MCQ Questions and answers on Physics-GK

21

Rate of doing work is called

A) Capacity B) Energy C) Power D) Current

Discuss

Answer & Solution

Answer: Option C

Solution:

In physics, power is the rate of doing work. It is the amount of energy consumed per unit time. The unit of power is the joule per second (J/s), known as the watt.

22

The energy associated with motion is called

A) Potential energy B) Kinetic energy C) Both A & B D) None of the above

Discuss

Answer & Solution

Answer: Option B

Solution:

The energy associated with motion is called kinetic energy.

23

The boiling point of water decreases at higher altitudes is due to

A) Low temperature B) Low atmospheric pressure C) High temprature D) High atmospheric pressure

Discuss

Answer & Solution

Answer: Option B

Solution:

The boiling point of water decreases at higher altitudes is due to low atmospheric pressure.

24

At boiling point of liquids, its

A) Temperature increases B) Atmospheric pressure increases C) Temperature remains constant D) Vapour pressure decreases

Discuss

Answer & Solution

Answer: Option C

Solution:

At boiling point of liquids, its temperature remains constant.

25

Contact force is another name for ________

A) Friction B) Magnetic force C) Electrostatic force D) Muscular force

Discuss

Answer & Solution

Answer: Option D

Solution:

Contact force is another name for Muscular force.

26

The rotational effect of a force on a body about an axis of rotation is described in terms of

A) Centre of gravity B) Centripetal force C) Centrifugal force D) Moment of force

Discuss

Answer & Solution

Answer: Option D

Solution:

The rotational effect of a force on a body about an axis of rotation is described in terms of moment of force.

27

At hill stations, the boiling point of water will be

A) Same as at sea level B) Less than that at sea level C) More than that at sea level D) Equal to the melting point of ice

Discuss

Answer & Solution

Answer: Option B

Solution:

The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.Thus, vapour pressure will equal atmospheric pressure at a comparatively low temperature. Thus, the boiling point of water is reduced less than at sea level.

28

Instrument used to measure the force and velocity of the wind is

A) Ammeter B) Anemometer C) Altimeter D) Audiometer

Discuss

Answer & Solution

Answer: Option B

Solution:

An anemometer is a device used for measuring wind speed and direction. It is also a common weather station instrument.

29

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

Discuss

Answer & Solution

Answer: Option C

Solution:

The melting point of ice decreases when pressure increases because when pressure is increased volume is decreased and volume of water is less than ice.

30

The wall of a dam is made thicker at the bottom than at the top because the pressure exerted by the water on the wall

A) Depends on the thickness of the wall B) Increases with height of the wall C) Increases with depth of the wall D) Depends on the area of the wall

Discuss

Answer & Solution

Answer: Option C

Solution:

The pressure applied to walls of the dam will be a function of the amount of water that is over that particular point on the wall. So water pressure is very large at the bottom due to its large depth. That's why dams are constructed thicker at their bottoms than at their tops.