A reversible heat engine receives 2 kJ of heat from a reservoir

A reversible heat engine receives 2 kJ of heat from a reservoir at 1000 K and a certain amount of heat from a reservoir at 800 K. It rejects 1 kJ of heat to a reservoir at 400 K. The net work output (in kJ) of the cycle is

We know that for reversible heat engine, change in entropy is always zero
That is ∆S = 0

Q₃	-		Q₁	+	Q₂		= 0
T₃			T₁		T₂

	1	-	2	-	Q₂	= 0
	400		1000		800

Q₂ = 0.4 kJ
W_Net = (Q₁ + Q₂) – Q₃ = (2 + 0.4) – 1 = 1.4 kJ.