JEE Main 2020 Physics question
Starting at temperature 300 K, one mole of an ideal diatomic gas ( = 1.4) is first compressed adiabatically from volume to . It is then allowed to expand isobarically to volume . If all the processes are the quasi-static then the final temperature of the gas (in ºK) is (to the nearest integer) ………….. .
Answer: 1819
Solution
T2 = 300 × .4 ≈ 909.4 K and T3 = 2T2 ≈ 1818.8 K, i.e. 1819 K (the paper's key is 1819; it lists the NTA answer as 1818).