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MHT CET 2026 (15 May, Shift 1) · P-V Diagrams & Cyclic Processes

P-V Diagrams & Cyclic Processes question from MHT CET 2026 (15 May, Shift 1)

Q8MHT CET 2026 · 15 MAY · SHIFT 1Medium

P-V Diagrams & Cyclic Processes

One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown. The change in internal energy of the gas during the transition is

Figure

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Answer: (b)

  1. Diatomic gas: ΔU=nCvΔT=52(PBVB−PAVA)\Delta U = nC_v\Delta T = \frac{5}{2}(P_BV_B - P_AV_A) using PV=nRTPV = nRT.
  2. PAVA=5×4=20 kJP_AV_A = 5 \times 4 = 20\ \text{kJ}, PBVB=2×6=12 kJP_BV_B = 2 \times 6 = 12\ \text{kJ}
  3. ΔU=52(12−20)=−20 kJ\Delta U = \frac{5}{2}(12 - 20) = -20\ \text{kJ}
  4. So the answer is (b) −20-20 kJ.
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