STATEMENT-1: There is a natural asymmetry between converting work to heat and converting heat to work.
and
STATEMENT-2: No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.
and
STATEMENT-2: No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.
- (A)STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1✓ Correct
- (B)STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1
- (C)STATEMENT-1 is True, STATEMENT-2 is False
- (D)STATEMENT-1 is False, STATEMENT-2 is True
Answer: (A)
Solution
STATEMENT-1 is true: Work can be completely converted to heat (e.g., through friction), but heat cannot be completely converted to work without some heat being rejected to a cold reservoir. This is the natural asymmetry.
STATEMENT-2 is true and is the Kelvin-Planck statement of the second law of thermodynamics. It explains why there is an asymmetry: complete conversion of heat to work in a cyclic process is impossible.
STATEMENT-2 correctly explains STATEMENT-1, as the impossibility of complete heat-to-work conversion is the reason for the asymmetry.
STATEMENT-2 is true and is the Kelvin-Planck statement of the second law of thermodynamics. It explains why there is an asymmetry: complete conversion of heat to work in a cyclic process is impossible.
STATEMENT-2 correctly explains STATEMENT-1, as the impossibility of complete heat-to-work conversion is the reason for the asymmetry.
JEE Advanced · 2008 · 13 Apr 2008 · Paper 2 · Single correct option