Question

Each one of the following changes will increase emf (or voltage) in a simple generator except
(a) increasing the number of turns in the armature coil
(b) winding the coil on a soft iron armature
(c) increasing the size of the gap in which the armature turns
(d) increasing the speed of rotation

Answer 1

Answer:

Arnature coil is driven by DC current to induct stator voltage, being rotation speed fixed by grid frequency, more turns will drive more voltage but voltage regulation will decrease exciter current. That is not alike transformer, whatsoever. If you wondering about DC generator, the excitation will be on stator and again will be regulated to keep output voltage constant, increasing number of turns will reduce the magnetic field required but will the ¨allowed¨ current due to smaller wire cross section area.