Electrical Engineering XYZ MCQ
In DC machine armature windings are placed on rotor, that is because of the necessity for:
- Compound motors
- Series motors
- Shunt motors
- All of these
Correct answer: 4. All of these
Explanation: In a DC machine, the armature windings are placed on the rotor due to the necessity for different types of DC motors – compound motors, series motors, and shunt motors.
- Compound Motors:
- In compound motors, there are both series and shunt field windings. The armature is placed on the rotor to allow for a combination of series and shunt field windings. This configuration provides the motor with characteristics of both series and shunt motors, allowing it to have good starting torque as well as a stable speed.
- Series Motors:
- In series motors, the armature is connected in series with the field winding. Placing the armature on the rotor is necessary to maintain this series connection. Series motors are known for their high starting torque, making them suitable for applications such as traction and certain industrial uses.
- Shunt Motors:
- In shunt motors, the field winding is connected in parallel (shunt) with the armature. Again, placing the armature on the rotor is necessary to maintain this configuration. Shunt motors are characterized by their relatively constant speed and are commonly used in applications where speed regulation is important.
Therefore, the armature windings being placed on the rotor is a design feature that accommodates the different requirements of compound, series, and shunt motors.