Aux 2 Unit 5 Quiz 1

Correct Answer:
B) The motor achieves a wide range of speeds with stable torque and efficiency

Explanation:
By varying both voltage and frequency, the motor can operate at various speeds while maintaining a stable torque and high efficiency, which is essential for effective and versatile motor control.

Correct Answer:
A) To maintain a constant magnetic flux and torque across different speeds

Explanation:
Varying both voltage and frequency proportionally maintains the V/f ratio, ensuring that the magnetic flux within the motor stays constant. This allows the motor to produce consistent torque across different speeds and operate efficiently.

Correct Answer:
C) It results in an imbalanced torque-speed relationship

Explanation:
If the frequency is varied while keeping the voltage constant, the voltage-to-frequency ratio (V/f) is altered. This affects the magnetic flux in the motor, leading to potential saturation or weakening of the magnetic field, which disrupts the torque production and overall motor performance.

Correct Answer:
B) It prevents overheating and allows stable torque production

Explanation:
Maintaining a constant V/f ratio ensures that the motor operates within its designed magnetic flux limits, providing stable torque and preventing excessive heating that could damage the motor.

Correct Answer:
B) It results in reduced torque and inefficient motor performance

Explanation:
Reducing the voltage while maintaining a constant frequency leads to a decrease in the magnetic field strength, which in turn reduces torque. This causes the motor to operate inefficiently and may result in unstable performance, especially under varying load conditions.

Correct Answer:
C) It leads to increased current and potential for motor stalling

Explanation:
When the voltage is reduced without adjusting the frequency, the current drawn by the motor may increase to compensate for the loss of torque. This can lead to overheating and potential stalling, reducing the motor's efficiency and lifespan.

Correct Answer:
C) The motor's magnetic field weakens, leading to reduced torque

Explanation:
Increasing frequency without a corresponding increase in voltage reduces the V/f ratio, weakening the magnetic field. This results in lower torque output and less effective motor operation.