The coefficient of coupling, denoted by k, is a dimensionless quantity that represents the degree of coupling between two inductors in a circuit. It is related to the mutual inductance (M) and the individual inductances (L1 and L2) by the formula:
\(k=\frac{M}{\sqrt{(L1\times L2)}}\)
Using the given values:
M = 3H
L1 = 4H
L2 = 9H
We can substitute these values into the formula to find the coefficient of coupling:
\(k=\frac{3}{\sqrt(4\times9)}\)
\(=\frac{3}{\sqrt 36}\)
\(=\frac{3}{6}\)
= 0.5
Therefore, the coefficient of coupling (k) is equal to 0.5.