Practice MCQ Questions and answers on Physics-GK

1

Hot water is poured simultaneously in four metallic tumblers painted outside with different points. After some time the water will be found to have cooled most in the tumbler painted.

A) Rough white B) Rough black C) Shining white D) Shining black

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

2

Which of the following criterion is used for any metal to be used as a cooking material ?

A) More specific heat B) More thermal conductivity C) Less thermal conductivity D) Less electrical conductivity

Discuss

Answer & Solution

Answer: Option B

Solution:

For a metal to be used as a cooking material, it is important to have more thermal conductivity. This is because metals with high thermal conductivity quickly and evenly distribute heat, which is crucial for cooking. It allows for efficient and uniform heating of the cooking utensil, ensuring that food is cooked thoroughly and at a consistent temperature

3

Heat from the sun reaches earth by the process of

A) Conduction B) Convection C) Radiation D) All of the above

Discuss

Answer & Solution

Answer: Option C

Solution:

Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is invisible.

4

Ocean currents are an example of

A) Convection B) Conduction C) Insulation D) Radiation

Discuss

Answer & Solution

Answer: Option A

Solution:

Ocean currents are an example of convection.

5

What type of heat transfer is boiling water?

A) Radiation B) Conduction C) Convection D) None of the above

Discuss

Answer & Solution

Answer: Option C

Solution:

When a pot of water is placed on the stove to boil, conduction heat warms up the pot, which then heats the water molecules inside. As these molecules heat, convection causes them to move away from the interior of the pot as they are replaced by cooler molecules.

6

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

Discuss

Answer & Solution

Answer: Option B

Solution:

Ventilators are provided near ceilings in the rooms of our houses because the air we breathe out is warm and rises out of the room through the ventilators. Cool fresh air rushes into the room through the doors and windows.

7

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

Discuss

Answer & Solution

Answer: Option B

Solution:

Wool does not allow heat to pass on from body to surrounding because it is a bad conductor of heat. So, the body is kept warm.

8

Plants are dried up in winter due to frost because

A) Evaporation does not take place B) Photosynthesis does not take place at such low temperature C) Respiration does not take place at low temperature D) There is mechanical loss of tissues and drought condition prevails

Discuss

Answer & Solution

Answer: Option D

Solution:

The rate of respiration is dependent on temperature: The warmer it is, the more a plant will respire. Extreme winter cold and frost are similar to summer drought in that frozen water is unavailable to the plant. The air is very dry as well.

9

A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it lose heat?

A) Conduction and convection only B) Conduction and radiation only C) Convection and radiation only D) Conduction, convection and radiation

Discuss

Answer & Solution

Answer: Option D

Solution:

A cup of hot coffee is placed on a metal table in a room can lose heat via conduction, convection and radiation.

10

In general, which is the cause of a land breeze?

A) Pressure B) Heat C) Temperature D) None of the above

Discuss

Answer & Solution

Answer: Option C

Solution:

Temperature is the cause of land breeze in general.