Electrical Engineering XYZ MCQs
A large series motor is never started without some mechanical load on it because otherwise it will:
- Draw too much current
- Develop excessive speed and damage itself
- Produce sparking at brushes
- Open fuse or circuit breaker
Correct answer: 2. Develop excessive speed and damage itself
Explanation: A large series motor has its field windings and armature connected in series, resulting in strong torque production when current flows. Without a load, there is nothing to restrain this torque, and the motor will accelerate to excessive speeds, potentially causing mechanical damage due to high rotational forces or disintegration. Series motors rely on the load to limit their speed; without a load, they can reach dangerous speeds quickly. This is why they are not started without some mechanical load.