Electrical Engineering XYZ MCQs
In DC machine armature windings are placed on rotor because of the necessity for:
- Commutation
- Electromechanical energy conversion
- Development of torque
- Generation of voltage
Correct answer: 1. Commutation
Explanation: In DC machines, the armature windings are indeed placed on the rotor. The primary reason for this arrangement is related to commutation. The process of commutation in a DC machine involves the reversing of current in the armature windings as they pass through the magnetic field created by the stator. This is necessary to maintain continuous torque in the direction of rotation. The commutator and brushes, which are part of the rotor assembly, facilitate this switching of current. If the armature windings were on the stator, the physical and electrical connections required for commutation would be much more complex and less efficient. Thus, placing the armature on the rotor simplifies the design and operation of the commutator and brushes.