Question

A beggar wrapped himself with a few layers of newspaper on a cold winter night. This helped him to keep himself warm because

• A. friction between the layers of newspaper produces heat.
• B. air trapped between the layers of newspaper is a bad conductor of heat.
• C. newspaper is a conductor of heat.
• D. newspaper is at a higher temperature than the temperature of the surrounding.

Answer 1

The correct option is B

air trapped between the layers of newspaper is a bad conductor of heat.

Explanation for Correct Answer:

Option (B):

1. A conductor is defined as a body that allows heat to flow through them easily.
2. This conduction is possible due to the presence of free particles inside the conductor, that participate in the transfer of heat from one point of the conductor to another.
3. Insulators are materials that hinder the free flow of particles from one point of the element to another.
4. If we transfer some amount of heat energy to such an element at any point, the heat remains at the initial location and does not get distributed across the surface.
5. The beggar wraps himself with a few layers of newspaper due to the fact that the newspaper is an insulator, meaning that it does not permit heat or cold to pass through it.
6. As a result, the beggar wraps himself in newspaper to prevent heat from his body from escaping and cold from the outside from entering his body.
7. Besides, there is air present between the layers of the newspaper.
8. Air is a bad conductor of heat which also prevents heat from his body to escape and cold from the outside to enter his body.

Explanation for Incorrect Answer:

Option (A):

1. Friction is the heat energy that occurs between two moving bodies.
2. In this case, no motion is involved.
3. Hence, friction is not present between the layers of the newspaper.

Option (C):

1. A newspaper is an insulator, meaning that it does not permit heat or cold to pass through it.
2. Hence, the newspaper is not a conductor of heat.

Option (D):

1. Here no external energy is applied to the newspaper.
2. Therefore, the newspaper is not at a higher temperature than the temperature of the surrounding.

Hence, the correct answer is option (B).