Internal energy change in an isothermal process: evaluate the statement Statement: “There is no change in internal energy in an isothermal process.” Decide whether this is correct for an ideal gas.
Mechanical Engineering
Thermodynamics
Difficulty: Easy
Choose an option
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AAgree (true for an ideal gas)
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BDisagree (false even for an ideal gas)
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CTrue only if pressure is constant
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DTrue only at very low temperatures
Answer
Correct Answer: Agree (true for an ideal gas)
Explanation
Concept/Approach
- For an ideal gas, internal energy depends only on temperature: ΔU = m cv ΔT.
- Isothermal ⇒ ΔT = 0 ⇒ ΔU = 0.
Final AnswerAgree — for an ideal gas, isothermal implies no change in internal energy.