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Question
Two bodies at different temperatures are mixed in a calorimeter. Which of the following quantities remains conserved?
Options
Sum of the temperatures of the two bodies
Total heat of the two bodies
Total internal energy of the two bodies
Internal energy of each body
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Solution
Total internal energy of the two bodies
When two bodies at different temperatures are mixed in the calorimeter, heat flows from one body to the other due to the temperature difference. This results in change in the internal energy of the individual bodies. There is no exchange of heat with the surrounding in the calorimeter. Thus, the total internal energy of the bodies remain conserved as no external work is done on them.
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