Question

A gas for which gamma is 4/3, is heated at constant pressure. The
percentage of heat supplied, used for external work is:
A) 25%
C) 75%
B) 60%
D) 40%​

Answer 1

Answer:

For a constant pressure heating process:

dq=du+dw

nC  

p

​  

ΔT=nC  

v

​  

ΔT+nRΔT

γ−1

γR

​  

=  

γ−1

R

​  

+R

Fraction of heat supplied used for external work is:

dq

dw

​  

=  

γ−1

R

​  

+R

R

​  

=  

γ

γ−1

​  

=  

3

4

​  

 

3

4

​  

−1

​  

=0.25

Percentage =0.25×100=25%

Explanation: