Question

Find the value of x if the Mutual inductance is x H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H. The coupling coefficient is 5.

(a) 10H

(b) 20H

(c) 16H

(d) 15H

I got this question in an internship interview.

This question is from Coupling Coefficient topic in portion Inductance in a DC Circuit of Basic Electrical Engineering

Answer 1

The correct option is (b) 20H

The best explanation: we know that:

k=M/sqrt(L1L2)

Substituting the values from the question, we get M=20H.