The point to be emphasized is that the dynamo does not create electricity (nor the pump water) but sets into motion something already existing by generating sufficient pressure to overcome the opposition to its movement.
Essential Parts of a Dynamo.—The dynamo in its simplest form consists of two principal parts:
1. The field magnet; 2. The armature.
Ques. What is the object of the field magnet?
Ans. To provide a field of magnetic lines or lines of force to be cut by the armature inductors as they revolve in the field.
Ques. What is an armature?