will refuse to start
will overheat in spots
will not come upto speed
will fail to pull into step
Answer is Right!
Answer is Wrong!
The correct answer is: A. will refuse to start
A three-phase synchronous motor has three windings that are evenly spaced around the stator. When these windings are energized with three-phase power, they create a rotating magnetic field. This magnetic field induces a current in the rotor, which causes the rotor to turn in the same direction as the magnetic field.
If one of the phases is short-circuited, the magnetic field will be distorted. This will cause the rotor to lose power and stop turning.
The other options are incorrect because:
- Option B: The motor will not overheat in spots. The motor will overheat as a whole, but this is not the reason why it will refuse to start.
- Option C: The motor will not come up to speed. The motor will not come up to speed because it will not be able to rotate in the same direction as the magnetic field.
- Option D: The motor will fail to pull into step. The motor will not fail to pull into step because it will not be able to rotate in the same direction as the magnetic field.