What is motor slip?

Motor slip refers specifically to the difference between the synchronous speed of a motor and its actual speed when it is under load. Synchronous speed is the theoretical speed at which the motor's magnetic field rotates, determined by the frequency of the AC power supply and the number of poles in the motor. However, when the motor is loaded, it cannot always reach this theoretical speed, resulting in what is termed "slip."

This difference is crucial because it indicates how efficiently the motor is operating. A small slip percentage typically denotes a motor that is operating efficiently, while a larger slip can indicate potential issues such as excessive load or other performance-related problems. Understanding slip is essential for diagnosing motor performance and ensuring that the motor operates within its designed parameters.

The other choices do not accurately define motor slip. The speed at which the motor runs without load doesn't capture the concept of slip, as slip specifically involves a comparative measure between two speeds. The rate of power loss may relate to motor efficiency but does not pertain directly to the concept of slip, and the speed range for normal operation doesn't clarify the relationship between synchronous and actual speeds.