Match List - I with List - II. Given V1 and V2 are initial and final volumes respectively. Choose the correct answer from the options given below :
- A-II, B-III, C-I, D-IV
- A-II, B-I, C-IV, D-III
- A-II, B-I, C-III, D-IV
- A-I, B-II, C-III, D-IV
Answer
(3) A-II, B-I, C-III, D-IV
Solution
Isothermal process of an ideal gas: ΔU = 0 ⇒ q = −w
A. Reversible expansion: wrev = -nRT V2V1 ⇒ q = nRT V2V1 ⇒ A-II
B. Free expansion (pext = 0): w = 0 and ΔU = 0 ⇒ q = 0 ⇒ B-I
C. Irreversible compression against constant pext: w = -pext V = -pext(V2 - V1) (positive, as V2 < V1) ⇒ C-III
D. Cyclic reversible process: entropy is a state function ⇒ S = qrevT = 0 ⇒ D-IV
∴ A-II, B-I, C-III, D-IV
Answer: (3)