Question

A gas for which $\gamma =\frac{4}{3}$, is heated at constant pressure. The percentage of total heat supplied for doing external work is

• A. 50 %
• B. 25 %
• C. 35 %
• D. 40 %

Answer 1

The correct option is B

25 %

$dQ=n{C}_{P}dT:dW=nRdT$

$\frac{dW}{dQ}=\frac{nRdT}{n{C}_{p}dT}=\frac{R}{C_p}$$1-\frac{c_v}{c_p}=1-\frac{1}{v}=1-\frac{3}{4}=\frac{1}{4}=25$