Heat is supplied to a rigid diatomic gas at constant pressure. The ratio of Δ Q: Δ U: Δ W is Δ Q = heat supplied, Δ U = change in internal energy, Δ W = work done during expansion (a) 5: 3: 2 (b) 2: 3: 5 (c) 7: 5: 2 (d) 2: 5: 7

Answer: (c). At constant pressure: Δ Q = nCpΔ T, Δ U = nCvΔ T, Δ W = nRΔ T. Rigid diatomic: Cp = 7/2R, Cv = 5/2R. Δ Q: Δ U: Δ W = 7/2: 5/2: 1 = 7: 5: 2 So the answer is (c) 7: 5: 2.

Heat is supplied to a rigid diatomic gas at constant pressure. The… | MHT CET 2026 (19 May, Shift 2)

Q14MHT CET 2026 · 19 MAY · SHIFT 2Medium

Thermodynamic Processes

Heat is supplied to a rigid diatomic gas at constant pressure. The ratio of $\Delta Q : \Delta U : \Delta W$ is $\{\Delta Q =$ heat supplied $, \Delta U =$ change in internal energy $, \Delta W =$ work done during expansion $\}$

Show answer and solution

Answer: (c)

At constant pressure: $\Delta Q = nC_p\Delta T$ , $\Delta U = nC_v\Delta T$ , $\Delta W = nR\Delta T$ .
Rigid diatomic: $C_p = \dfrac{7}{2}R$ , $C_v = \dfrac{5}{2}R$ .
$\Delta Q : \Delta U : \Delta W = \dfrac{7}{2} : \dfrac{5}{2} : 1 = 7 : 5 : 2$
So the answer is (c) $7 : 5 : 2$ .

Report a mistake

Thermodynamic Processes question from MHT CET 2026 (19 May, Shift 2)

More questions on Thermodynamic Processes