An engine operates between a hot reservoir at 500K and a cold reservoir at 300K. In one cycle it absorbs 4.0×103J of heat and performs 2.0×103J of work.
(i) Calculate the actual efficiency of the engine.
(ii) Determine the maximum possible efficiency for any engine working between these two temperatures.
(iii) State whether the given engine is possible under the Second Law, giving a brief reason.