A thermodynamic system is taken from state A to B along ACB and is brought back to A along BDA as shown in the P-V diagram. The net work done during the complete cycle is given by the area 

• A

  ${\mathrm{P}}_1{\mathrm{ACBP}}_2{\mathrm{P}}_1$

• B

  ${\mathrm{ACBB}}^{\mathrm{′}}{\mathrm{A}}^{\mathrm{′}}\mathrm{A}$

• C

  $\mathrm{ACBDA}$

• D

  ${\mathrm{ADBB}}^{\mathrm{′}}{\mathrm{A}}^{\mathrm{′}}\mathrm{A}$