Which of the following options regarding area under the graph is/are correct ?

Options

A. The area under the V us P graph will give magnitude of work involved in the process
B. The area under T us S graph will give magnitude of heat exchange involved if the process occurs reversibly
C. The area under S us T graph will given magnitude of heat exchange involved in the process.
D. The area under P us V graph will give magnitude of free energy change in an isothermal process

Answer

B