Question

Two bodies are said to be in thermal equilibrium if they have equal

• A. temperature
• B. heat energy
• C. mechanical energy

Answer 1

The correct option is A temperature

Temperature is virtue by which we classify hot and cold bodies. A body at a higher temperature is hot and vice versa. When two bodies are at the same temperature then they both are equally hot or cold. This makes it impossible for heat energy to flow, as we know, heat can flow only from a hot body to a cold body. This state in which the two bodies remain at the same temperature and no heat flows through the boundary is called a thermal equilibrium.
Mechanical Energy is the sum of Kinetic and Potential Energy of a body. It has nothing to do with the thermal equilibrium of a body.