Question

What is the relation between the overload capacity and magnetizing current?

(a) overload capacity is directly proportional to the magnetizing current

(b) overload capacity is indirectly proportional to the magnetizing current

(c) overload capacity is directly proportional to the square of the magnetizing current

(d) overload capacity is indirectly proportional to the square of the magnetizing current

I have been asked this question in unit test.

The query is from Dispersion Coefficient in chapter Three Phase Induction Motor of Design of Electrical Machines

Answer 1

Correct option is (a) overload capacity is directly proportional to the magnetizing current

To explain: Overload capacity is directly proportional to the magnetizing current. Overload capacity increases the magnetizing current and this increases the dispersion coefficient and this gives a poor power factor.