According to second law of thermodynamics: - Vidyadip

MCQ

According to second law of thermodynamics:

✓
A heat engine cannot have efficiency equal to $1.$
B
A refrigerator $($or heat pump$)$ could have infinite value of coefficient of performance.
C
A heat engine can convert heat fully in to work.
D
Heat can flow from cold to hot body.

✓

Answer

Correct option: A.

A heat engine cannot have efficiency equal to $1.$

Second law puts limitation on the efficiency of a heat engine and on the coefficient of performance of a refrigerator. Heat engine cannot have efficiency equal to $1$ and a refrigerator cannot have infinite value of coefficient of performance.

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