The temperature of an ideal gas at an initial pressure P1 and volume V1 is increased at constant volume until the pressure is doubled.

The temperature of an ideal gas at an initial pressure P1 and volume V1 is increased at constant volume until the pressure is doubled. The gas is then expanded isothermally until the pressure drops to is original value, where it is compressed at constant pressure until the volume returns to its initial value. (a) sketch these process in the P-V plane and in the P-T.