Three moles of an ideal gas `(C_p=7/2R)` at pressure, `P_A` and temperature `T_A` is isothermally expanded to twice its initial volume. It is then compressed at constant pressure to its original volume. Finally gas is compressed at constant volume to its original pressure `P_A`.
(a) Sketch P-V and P-T diagrams for the complete process.
(b) Calculate the net work done by the gas, and net heat supplied to the gas during the complete process.

Options

A.
B.
C.
D.

Answer

A, C

Explanation

Let the process start from initial pressure `P_(A)`, volume `V_(A)` and temperature `T_(A)`,
`I:` Isothermal expansion `(PV=` constant `)` at temperature `T_(A)` to twice the initial volume `V_(A)`.
`II:` Compression at constant pressure `P_(A)//2` to original volume `V_(A)(i.e., V prop T)`
`III:` Isochoric process `(`at volume `V_(A) )` to initial conditions `(i.e., P prop T )`