(a) List the different combinations of motor-generators that are often made, to suit load conditions. (6)

(b) A diesel engine has a measured indicated power of 7.5 kW and a mechanical efficiency of 85 percent. It drives a generator which supplies a lamp load at 110V.

How many 60W lamps can be supplied, if the efficiency of the generator is measured to be 88 percent? Find the total load current. (10)