Question

In an AC generator, name the part which has the following functions:
(a) intensifies the magnetic field.
(b) maintains electrical contact between the rotating parts and the external circuit.

Hint:

Remember the difference for generators: AC Generator uses \textbf{Slip Rings} (for alternating current). DC Generator uses a \textbf{Split-Ring Commutator} (to reverse the current every half rotation and produce direct current).

Answer 1

(a) Intensifies the magnetic field:
The part that intensifies the magnetic field is the soft iron core. The insulated copper coil (armature) is wound on a soft iron core. This core becomes a strong electromagnet when current is induced, greatly strengthening the overall magnetic field and leading to a higher induced e.m.f.
(b) Maintains electrical contact between the rotating parts and the external circuit:
This function is performed by two components working together: the slip rings and the carbon brushes.
- The slip rings are two continuous metal rings that are attached to the ends of the armature coil and rotate with it.
- The carbon brushes are stationary blocks of carbon that press lightly against the rotating slip rings, conducting the current from the coil to the external circuit.