An ideal gas expands into a vacuum in a rigid vessel. As a result there is :

Question

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 A: a change in entropy. Therefore the correct answer is A.