Answer & Solution
Answer: Option C
Solution:
Slip in an induction motor is the difference between the synchronous speed (the speed of the rotating magnetic field) and the rotor speed (the actual speed of the motor shaft). It's usually expressed as a percentage.
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Option A (0.04 %): This is too low. A slip this small would mean the rotor is almost running at the same speed as the rotating magnetic field, which isn't typical for medium-sized induction motors under load.
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Option B (0.4 %): This is also quite low. It's more typical of very large induction motors or motors operating with very light loads.
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Option C (4 %): This is the
most common slip value for medium-sized induction motors under normal operating conditions. It provides a good balance between torque production and efficiency.
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Option D (14 %): This is a very high slip value. Such high slip is
not ideal because it causes more losses in the motor, creates excessive heat, and reduces efficiency. It might be found in specific applications requiring high starting torque.
In summary: For medium-sized induction motors, a slip of around 4% is the
most realistic and commonly encountered value.
