Electrical Engineering XYZ MCQs
The power factor of squirrel cage induction motor is:
- Low at heavy loads only
- Low at light loads only
- Both of the above
- Low at rated load only
Correct answer: 2. Low at light loads only
Explanation: The power factor of a squirrel cage induction motor is generally low at light loads because the motor draws a significant amount of magnetizing current to establish the magnetic field, compared to the actual useful power drawn (real power). As the load increases, the proportion of useful power increases relative to the magnetizing current, improving the power factor. Hence, the power factor is lowest when the motor is under light load and improves as the load increases. At heavy or rated loads, the power factor is significantly higher than at light loads.