Question

Two insulting cylinders A and B fitted with pistons contain equal amounts of an ideal diatomic gas at temperature 300K. The piston A is free to move, while that of B is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise in temperature of the gas in A is 30K. Then the rise in temperature of the gas in B is.

• A. 30K
• B. 18K
• C. 50K
• D. 42K

Answer 1

Answer: (D)

42K

Answer 2

For cylinder A. For cylinder B

dQ = nC_PdT₁ dQ = nC_VdT₂

= n(C_V+R) dT₁

∴ nC_VdT₂ = n(C_V+R) 30

$\therefore$ $d T _ { 2 } = \frac { \left( C _ { v } + R \right) 30 } { C _ { v } }$

For diatomic gas $C _ { v } = \frac { 5 } { 2 } R$

$\therefore$.

Hence (4)