Question

A three phase induction motor is sometimes calles a generalized transformer in so far as voltage and frequency transformation has been concerned. How a three phase induction motor operates when rotor frequency is equal to stator frequency?

(a) It will not operate

(b) It will operate as induction motor only

(c) It will operate as induction generator

(d) It will operate in braking mode

This question was posed to me at a job interview.

This is a very interesting question from Principle of Operation topic in chapter Induction Machines of Electrical Machines

Answer 1

Right option is (a) It will not operate

For explanation I would say: As the rotor and stator frequencies are equal, there will be no slip and so the zero emf will be produced.