Q.39. Which combination of the following statements is correct?
P: A gas cools upon expansion only when its Joule-Thomson co-efficient is positive in the temperature range of expansion.
Q: For a system undergoing a process, its entropy remains constant only when the process is reversible.
R: The work done by a closed system in an adiabatic process is a point function.
S: A liquid expands upon freezing when the slope of its fusion curve on Pressure.
Temperature diagram is negative.
(A) R and S
(B) P and Q
(C) Q, R and S
(D) P,Q and R
Answer: (A)
Explanation:
