The value of Cₚ−Cᵥ is 1.09R for a gas sample in state A and 1.00R in state B. Let Tₐ, Tᵦ be the temperatures and Pₐ, Pᵦ the pressures in states A and B. Then:
Physics · Thermodynamics
JEE Mains NEET

Question

The value of Cₚ−Cᵥ is 1.09R for a gas sample in state A and 1.00R in state B. Let Tₐ, Tᵦ be the temperatures and Pₐ, Pᵦ the pressures in states A and B. Then:

G1 Physics · Accepted Answer

Use the first law Q=ΔU+W (W by the gas), ΔU=nCᵥΔT for an ideal gas, and the appropriate process relation. For Carnot devices, let T₁ be the cold-reservoir temperature and T₂ be the hot-reservoir temperature; η=1−T₁/T₂ and COP=T₁/(T₂−T₁). Evaluating the given data/statements gives D: Pₐ > Pᵦ and Tₐ< Tᵦ. Therefore the correct answer is D.