A diatomic ideal gas is used in a carnot engine as the working substance. If during the adiabatic expansion part of the cycle, the volume of the gas increases from V to 32 V, the efficiency of the engine is ……………… .

Options

A. 0.25
B. 0.5
C. 0.75
D. 0.99

Answer

c

Explanation

`TV^(gamma-1)="constant"`
`rArr" "(T_(2))/(T_(1))=((V_(1))/(V_(2)))^(gamma-1)=((1)/(32))^((7)/(5)-1)`
`(T_(2))/(T_(1))=((1)/(2^(5)))^((2)/(5))=(1)/(4)`
`"Efficiency "eta=1-(T_(2))/(T_(1))=1-(1)/(4)=0.75`