Question

Find the coupling coefficient if the Mutual inductance is 20H, the inductance of coil 1 is 2H and the inductance of coil 2 is 8H.

(a) 5

(b) 20

(c) 2

(d) 8

The question was posed to me by my school teacher while I was bunking the class.

Query is from Coupling Coefficient topic in section Inductance in a DC Circuit of Basic Electrical Engineering

Answer 1

Right choice is (a) 5

Easiest explanation: we know that:

k=M/sqrt(L1L2)

Substituting the values from the question, we get k=5.