Ques. 1JEE Main 2025, 24 January (Evening Shift)
Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the correct answer from the options given below :
- Both (A) and (R) are true and (R) is the correct explanation of (A)
- Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
- (A) is false but (R) is true
- (A) is true but (R) is false
Answer
(3) (A) is false but (R) is true
Solution
Adiabatic Q=0 U=-W.
[figure]
(A): compression W<0 U>0 temperature rises (TV -1 = const) (A) is false
(R): free expansion: W=0, Q=0 (adiabatic), cannot reverse by itself (irreversible) (R) is true
(A) is false but (R) is true
Answer: (3)