12) The rotor of a salient pole alternator has 12 poles. The number of cycles of e.m.f. in one revolution will be :\n(Hint: Two-pole alternator will generate one cycle of e.m.f. in one rotation)

13) In large sized alternators, dampers are used to :

14) The number of electrical degrees which passes through in one revolution of a 6-pole alternator is :

15) The waveform of the e.m.f. generated by an alternator should be :

16) The field circuit of a hydro alternator is supplied with :