Question

For both lap and wave windings, there are as many commutator bars as the number of
1. slots
2. armature conductors
3. windings elements
4. Poles

Answer 1

Correct Answer - Option 2 : armature conductors

Commutator:

• In the case of the DC generator, the commutator is used to convert generated AC in armature into DC
• In the case of DC motor, the commutator is used to convert DC to A.C
• The commutator acts as a mechanical rectifier or inverter which changes the polarity of supply/generated emf.
• In a DC generator, the commutator converts the alternating current into the direct current so that AC voltage developed in the armature.
• In a DC motor, the commutator converts the direct current into alternating current so that AC voltage developed in the armature.
• The commutator requires frequent maintenance.
• Due to the limitation of the commutator dc generators are not usually designed beyond 650 V.

• The physical connection to the armature winding is made through a commutator-brush arrangement.
• The function of a commutator in a dc generator is to collect the current generated in armature conductors.
• While in the case of a dc motor, the commutator helps in providing current to the armature conductors.
• A commutator consists of a set of copper segments that are insulated from each other.
• The number of segments is equal to the number of armature conductors. Each segment is connected to an armature coil and the commutator is keyed to the shaft.