In an isothermal process internal energy of the system:
Correct answer: C. Remain the same
- A. Decreases
- B. Increases
- C. Remain the same
- D. Becomes zero
Explanation
The internal energy of an ideal gas depends only on its temperature, so in an isothermal process it remains the same and all the heat absorbed is converted into work. It does not become zero, since the molecules still have kinetic energy.
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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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