The Armature of a Generator
A generator has 500 turns
on the armature, which rotates at 1500 rpm in a magnetic field of magnitude
0.85 T (the field is alternately parallel and perpendicular to the coils
on the armature as it rotates). The generator produces an effective AC
voltage of 120 kV. What is diameter of the armature?
Solution:
The emf produced by the
rotating armature is
The effective voltage is
the root-mean-square (rms) voltage, which is the maximum value divided
by the square root of 2:
