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UPSC General Science

Thermal Equilibrium Definition and Examples

Thermal equilibrium is a state in which the temperature of a system is the same throughout and no heat flows between its parts.

Jan 16, 2023

2 min read

Thermal equilibrium is a state in which two systems in thermal contact with each other have reached the same temperature, meaning that there is no net flow of heat energy between the two systems. When two systems are in thermal equilibrium, they are at the same temperature and there is no longer any heat energy flowing from one system to the other. 




An example of thermal equilibrium is when a hot cup of coffee is placed on a table. Initially, heat energy will flow from the coffee to the table, causing the temperature of the coffee to decrease and the temperature of the table to increase. As time goes on, the temperature of the coffee and the table will eventually reach a point where they are the same, and there is no longer any net flow of heat energy between them. At this point, the coffee and the table are said to be in thermal equilibrium.


Another example could be a cold bottle of water placed in a room with ambient temperature, the bottle will release heat to the room and the room will release heat to the bottle, until they reach the same temperature, that is thermal equilibrium.

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