Question

A feature common to both AC and DC generator is:
A. Split rings
B. Electrical energy is converted to mechanical energy
C. Slip rings
D. Mechanical energy is converted to electrical energy

Answer 1

Hint: Recall that both AC and DC generators are used to power motors, and motors convert electrical energy to mechanical energy. Also, split rings change the current direction periodically whereas slip rings act just as a connection between the rotor and stator parts. Additionally, remember that in the DC generator, current is induced only in the rotor part, whereas in AC generator current may be induced in both rotor and stator parts, so this should help you decide where the split and slip rings are used and ultimately deduce the correct choice.

Complete answer:
We know that both the AC and DC generators have a moving rotor and a stationary stator that have various other components appended to them.
Let us go through this question by looking at the correctness of each option.
The first option suggests that both AC and DC generators have split rings. This is untrue.
Split rings make the current change direction every half-rotation whereas a slip ring commutator merely maintains a connection between the rotor and the stator. Now, we know that alternating current AC, is the flow of electric charge that periodically reverses direction, and direct current DC is the flow of electric charge in only when direction. Rotations produce current flowing in alternate directions every half rotation and this only needs to be conveyed to the stator in an AC generator, which thus uses slip rings. In order to confine the current in a DC generator to one direction, we need something that will nullify the reverse current effect every half rotation. This is done by the split rings.
This means that even the third option is untrue since AC and DC generators exclusively use slip rings and split rings respectively.
Now, we know that both the AC and DC generators have a rotor and a stator part. The stator part is usually an external circuit that is powered by the dynamics of the rotor. This means that we mechanically rotate the rotor part to induce current in the rotor and generate a flow of electricity in the stator part. This is a feature common to both the generators.

Thus, the correct choice would be D. Mechanical energy is converted to electrical energy.

Note:
Do not get confused between a generator and a motor. A generator converts mechanical work to electrical energy whereas a motor utilizes electrical energy to produce mechanical energy. An AC generator and motor produce alternating current and utilize alternating current to produce mechanical output respectively, whereas the DC generator and motor produce direct current and utilize direct current to produce mechanical output respectively.