Two 36 AC generators are such that one has twice the linear dimensions of the other. The field windings of each are excited to give identical sinusoidal air gap flux density waveform. Both have the same number of stator slots and identical winding patterns. The conductors per slot in big generator in K times that of the smaller one. The value of K to get equal no-load voltage at same frequency is (a) 8 (b) 8 (c) 호 (d) 1/4 1/2

In a Three-phase alternator, a given field current produces an armature current of 250 A on short-circuit and a generated e.m.f. of 1500 V on open-circuit. Calculate the terminal p.d. when a load of 250 A at 6.6 kV and 0.8 p.f. lagging is switched off. Calculate also the regulation of the alternator at the given load.   Subject: Electrical engineering

A 6-pole, 3-phase, 60-cycle alternator has 12 slots per pole and four conductors per slot. The winding is 5/6 pitch. There are 2,500,000 maxwells (0.025 weber) entering the armature from each north pole, and this flux is sinusoidally distributed along the air gap. The armature coils are all connected in series. The winding is wye-connected. Determine the open circuit emf of the alternator.

If a 3-phase short circuit occurs at the terminals of an alternator, the current in the armature circuit increases suddenly to a large value.   Select one: True False