From First Law of thermodynamics,
ΔQ=ΔU+Δw
ΔQΔw=1−ΔQΔU=1−ncpΔTncvΔT
=1−R+cvcv
=R+cvR
As, ncv=Cv
ΔQΔw=Cv+nRnR
JEE Main 2019 — Physics Thermodynamics
n moles of an ideal gas with constant volume heat capacity Cv undergo an isobaric expansion by certain volume. The ratio of the work done in the process, to the heat supplied is:
Held on 10 Apr 2019 · Verified 6 Jul 2026.
Cv+nR4nR
Cv−nR4nR
Cv+nRnR
Cv−nRnR
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