n moles of a monoatomic gas is carried round the reversible rectangular cycle ABCDA as shown in the diagram. The temperature at A is `T_0`. The thermodynamics efficiency of the cycle ____

Options

A. `15%`
B. `50%`
C. `20%`
D. `25%`

Answer

B

Explanation

For n moles of monoatomic gas
At A temperature =`T_0`, Volume =`V_0` , Pressure = `P_0`
At A, `P_0V_0 =nRT_0` (cold)
At B, `2P_0V_0=nRT` (high) =T.=`2T_0`
Maximum thermal efficiency of the reversible engine of this carnot.s cycle .
`=eta=1-T_0/T=1-T_0/(2T_0)=1/2`=50%