Draw on a P-V diagram the following processes. Label accurately each point in the four steps of the cycle using p,V,T for variables e.g. Va. The working substance is a perfect gas. Start from A. Show direction of change using arrow heads.

Step 1: Revesible adiabatic compression from point A to B.

Step 2: Reversible isochoric pressure increase from point B to C; heat is absorbed in this step.

Step 3: Reversible adiabatic expansion from C to D.

Step 4: Reversible isochoric pressure decrease from D to A; heat is released in this step.

Derive an expression for the efficiency of this heat engine in terms of the heat capacities Cv abd Cp, pressures and volumes based on the labels you used above in its simppliest terms.