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When does a system lose energy to its surroundings and its internal energy decreases?

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प्रश्न

When does a system lose energy to its surroundings and its internal energy decreases? 

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उत्तर

When the system does some work to increase its volume, and no heat is added to it while expanding, the system loses energy to its surroundings and its internal energy decreases.

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अध्याय 4: Thermodynamics - Very Short Answer

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