An ideal gas with γ = 4/3 is heated at constant pressure. What percentage of supplied heat goes into external work?
Physics · Mixed Chapter
JEE Main Practice

Question

An ideal gas with γ = 4/3 is heated at constant pressure. What percentage of supplied heat goes into external work?

G1 Physics · Accepted Answer

Step 1: At constant pressure, heat supplied Q = nCₚΔT. Step 2: Work by gas W = PΔV = nRΔT. Step 3: W/Q = R/Cₚ = (Cₚ−Cᵥ)/Cₚ = 1−1/γ. Step 4: W/Q = 1−3/4 = 1/4 = 25%.