JEE Main · 2025 · 29 Jan 2025 · Shift 1 · Heat & Thermodynamics

The workdone in an adiabatic change in an ideal gas depends upon only :

(A)change in its pressure
(B)change in its specific heat
(C)change in its volume
(D)change in its temperature✓ Correct

Answer: (D)

Solution

For an adiabatic process, no heat is exchanged with the surroundings, so

Q = 0

. The first law of thermodynamics states

Q = Δ U + W

so for an adiabatic change

W = - Δ U

For an ideal gas, the internal energy depends only on temperature,

Δ U = n C_{V} Δ T

W = - n C_{V} Δ T

The work done in an adiabatic change is fixed entirely by the change in temperature of the gas.

JEE Main · 2025 · 29 Jan 2025 · Shift 1 · Single correct option

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