1. The efficiency of a cyclic engine is given by the work done by the engine, divided by the heat intake from the surroundings. One Carnot engine drives another in series. Draw a schematic diagram of the combined engine and give an expression for the overall efficiency of this arrangement which contains only the efficiencies of the individual engines. 3. Hi, I have managed to draw the diagram but am really struggling with the next bit of the question. Let e1, e2 be the efficiencies of engions 1 and 2 respectively and let e be the overall efficiency. I know that e[tex]\ 1=w1/Q_H and e2=w2/(Q_h-w1)[/tex] but I am struggling to find e in terms of e1 and e2, please help.