The excess flux in synchronous motor is neutralized by ________

Question

Examoogle · Accepted Answer

Option A: armature winding by drawing demagnetizing component of the current from ac supply

Explanation & Concepts:
The correct answer is A. In synchronous motors, the excess flux is neutralized by the armature winding drawing a demagnetizing component of the current from the AC supply.

Working Principle: When an AC current flows through the armature winding of a synchronous motor, it generates a magnetic field. If the load increases beyond the synchronous capability, the armature current must draw a component that reduces the magnetic flux produced by the field winding, which is achieved by pulling a demagnetizing component from the supply.

Key Formulas: $F = \frac{B \cdot I \cdot L}{l}$ — Force on the conductor; $\Phi = B \cdot A$ — Magnetic flux linkage

Key Points: Synchronous motors operate at a constant speed regardless of load.; Demagnetizing current helps to prevent the motor from exceeding its synchronous speed.

Advantages: High efficiency under constant load; Maintenance-free operation due to no brushes

Disadvantages: Requires a complex control mechanism; Limited operational range

Applications: Industrial drives; Power generation in hydroelectric plants

Additional Info: Standard supply voltages for AC motors vary widely; understanding local standards is crucial.. Option B is incorrect as magnetizing current increases the magnetic flux, which is not needed for neutralizing excess flux.

Answer: A is correct — The demagnetizing component from the armature winding effectively neutralizes any excess magnetic flux in synchronous motors.

Exam Tip: Understanding the fundamental principles of magnetic circuits can help in grasping motor functionalities efficiently.

Examoogle · Answer

Option B: armature winding by drawing magnetizing component of the current from ac supply

Examoogle · Answer

Option C: field winding by drawing demagnetizing component of the current from dc supply

Examoogle · Answer

Option D: field winding by drawing magnetizing component of the current from dc supply

Correct Answer

Discussion (0)

Correct Answer

Related Questions

Discussion (0)