(a) Differentiate between resistance, inductance and impedance in an a.c. circuit. (6)

(b) A 4-pole, 32 conductor, lap-wound DC shunt generator with terminal voltage of 200 V delivering 12 A to the load has R_a = 2 and field circuit resistance of 200Ω . It is driven at 1000 RPM. Calculate (10)

(i) the flux per pole in the machine.

(ii) If the machine has to be run as motor with the same terminal voltage and drawing 5 A from mains, maintaining the same magnetic field, find the speed of the machine.