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 :

19) The frequency generated by a 8-pole alternator rotating at 600 r.p.m. will be

20) The frequency of voltage generated by an alternator having 4 poles and rotating at 1800 R.P.M. is

21) A 50 Hz alternator will run at the greatest possible speed if it is wound for _____ poles