(a) Write down the efficiency for a Carnot cycle as a function of (i) the heat flows to and from the reservoirs and (ii) the temperatures of the two reservoirs. (b) Describe the working of an Otto engine and efficiency for the air stan- dard Otto cycle as a function of temperature as well as volume. Start by sketching this cycle in a standard P -V diagram. Explain the four steps of this cycle in terms of associated temperature and volume changes as well as the heat exchanged with external reservoirs. (c) Compare the Carnot and the Sterling cycle using P -V diagram.