Solution: a) The description of the processes between particular points is the following:

0–1 : intake stroke isobaric and isothermal process

1–2 : compression of the mixture adiabatic process

2–3 : mixture ignition isochoric process

3–4 : expansion of the exhaust gas adiabatic process

4–1 : exhaust isochoric process

1–0 : exhaust isobaric process