Question

Two inductors having self inductances, $2\text{mH}$ and $8\text{mH}$ are arranged such that the mutual inductance is $2\text{mH}$. Find the coupling constant.

• A. $\frac{1}{3}$
• B. $\frac{1}{4}$
• C. $\frac{1}{2}$
• D. $\frac{1}{5}$

Answer 1

The correct option is C $\frac{1}{2}$

We know that,

$M=K\sqrt{L_1{L}_2}$

$\Rightarrow 2=K\sqrt{2\times 8}$

$\therefore K=\frac{1}{2}$

Hence, option $\left(C\right)$ is the correct answer.