Question

The slip-speed of a 3-\(\phi\), cage, 50 Hz, induction motor is 20 rpm at no-load. If slip-speed is doubled due to load, then the electrical equivalent of mechanical load will

• A. remain same
• B. be exactly doubled
• C. be more than doubled
• D. be less than halved

Hint:

Electrical load \( \propto \text{slip}^2 \); doubling slip doesn’t double the load — it increases it sharply.

Answer 1

The Correct Option is D

The electrical equivalent of mechanical load is proportional to the square of the slip. If slip doubles, equivalent load increases more than four times, which effectively means that for a given change in speed, the electrical load changes significantly — not linearly.