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 :

17) When a coil / conductor moves at right angle to the magnetic flux, the induced e.m.f. will be :

18) Salient pole type rotors as compared to the cylindrical pole type rotors are :