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MHT CET 2026 (16 Apr, Shift 2) · Degrees of Freedom & Internal Energy

Degrees of Freedom & Internal Energy question from MHT CET 2026 (16 Apr, Shift 2)

Q4MHT CET 2026 · 16 APR · SHIFT 2Medium

Degrees of Freedom & Internal Energy

A rigid diatomic gas having molar mass m is contained in an insulated container. The container is moving with velocity V. If it is stopped suddenly, the change in temperature is (R - gas constant)

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Answer: (c)

  1. Insulated container: the bulk KE of the gas becomes internal energy, 12(nm)V2=nCvΔT\frac{1}{2}(nm)V^2 = nC_v\Delta T.
  2. Rigid diatomic: Cv=52RC_v = \frac{5}{2}R.
  3. 12mV2=52R ΔT⇒ΔT=mV25R\frac{1}{2}mV^2 = \frac{5}{2}R\,\Delta T \Rightarrow \Delta T = \frac{mV^2}{5R}
  4. So the answer is (c) mV25R\frac{mV^2}{5R}.
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