In which process the work is done on the cost of internal energy?
Correct answer: D. Adiabatic process
- A. Isochoric process
- B. Isobaric process
- C. Isothermal process
- D. Adiabatic process
Explanation
In an adiabatic process no heat enters or leaves, so by the first law any work done by the gas must come from its internal energy, which falls. In an isothermal process the energy instead comes from heat absorbed, and in an isochoric process no work is done at all.
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About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
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