Question

State (i) two dissimilarities, and (ii) two similarities between a D.C motor and an A.C generator.

Answer 1

Two dissimilarities between D.C. motor and A.C. generator:

D.C motor	A.C generator
1. Converts direct current electrical energy into mechanical energy.	Converts mechanical energy into electrical energy.
2. The magnetic force is only able to flow in one direction, so the motor spins in only one direction.	The turning of a coil in a magnetic field produces motional emfs in both sides of the coil which add. Since the component of the velocity perpendicular to the magnetic field changes sinusoidally with the rotation, the generated voltage is sinusoidal or AC.

Similarities are:

• They both rely on the principle of electromagnetic in induction.
• The both contain coils of wire magnets or electromagnets and they both have rotating parts.
• The AC generator will probably work as an AC motor and the DC motor will probably work as a DC generator.