A 4 pole, 50 Hz Induction Motor Has a Slip of 5%. The Speed of motor is | Induction Motor MCQ#8

A 4 pole, 50 Hz Induction Motor Has a Slip of 5%. The Speed of motor is:

1. 1425 RPM
2. 1500 RPM
3. 1578 RPM
4. 1788 RPM

Correct answer: 1. 1425 RPM

The basic formula for formula for Synchronous Speed of Induction Machine is: η_sync= 120*f /P

η_sync= 120*f /P = 120 * 60/4 = 1500 RPM

η_m = (1-s) * η_sync

Here s = 0.05

η_m = (1 – 0.05) * 1500 = 0.95 * 1500 = 1425 RPM