Question

Suppose a body A at a higher temperature is brought into contact with another body B at a lower temperature, then which among the following are true?

• A. Molecules of body A becomes less active.
• B. The heat flow is from body A to body B.
• C. Molecules of body A becomes more active.
• D. The heat flow is from body B to body A.

Answer 1

Answer: (A), (B)

The correct options are
A Molecules of body A becomes less active.
B The heat flow is from body A to body B.

A body at a higher temperature has more active molecules than a body at a lower temperature and also heat flows from a body at higher temperature to a body at lower temperature. Before A and B comes in contact, A has more active molecules. When A and B are brought in contact, heat flows from body A to body B and the temperature of B increases. Hence, the molecules of B will become more active. Also, the temperature of A decreases. Hence, the molecules of A becomes less active.