Question

A gas is compressed isothermally at 400K, from 0.3Mpa to 4Mpa is then cooled isobarically to 290K. After that it is expanded adiabatically to 0.9 Mpa. Later expanded at constant temperature to the initial value of pressure. Finally heated isobarically to 400K. Draw the PV diagram and calculate the overall work done, change in internal energy and heat supplied. Data: Cp 3.7R and C=2.7R.

Answer 1

Since in P-V curves area under the cycle is equal to work done therefore work done by the gas is equal to P

Line AB and CD are isochoric line, line BC and DA are isobaric line.

∴ the T-V curve and P-T curve are drawn as shown.