What formula is used to find the Percentage of Slip in an Induction Motor?

The formula used to find the Percentage of Slip in an Induction Motor is derived from understanding the relationship between synchronous speed (Ns) and rotor speed (Nr). The correct formula for calculating slip percentage is represented by:

Slip% = ((Ns - Nr) / (Ns)) * 100.

This formula essentially measures the difference between synchronous speed and rotor speed as a fraction of the synchronous speed, allowing for the representation of slip as a percentage.

In induction motors, the synchronous speed (Ns) is the speed of the rotating magnetic field created by the stator, while the rotor speed (Nr) is the actual speed at which the rotor turns. The difference between these two speeds indicates how much the rotor is lagging behind the rotating magnetic field, which is crucial for assessing the performance of the motor.

Using this formula provides insights into the motor's efficiency; a higher percentage of slip indicates that the motor is not effectively converting electrical input into mechanical output, which can be critical in various applications.

The other options presented either miscalculate the relationship between the speeds or do not represent slip in a fraction of synchronous speed, leading to incorrect interpretations of slip in an induction motor context.