Question

Two inductors of equal inductance $10\text{mH}$ are connected together in a series combination so that their magnetic fields aid each other. Their mutual inductance is given as $5\text{mH}$. Calculate the total inductance of the series combination.

• A. $10\text{mH}$
• B. $20\text{mH}$
• C. $30\text{mH}$
• D. $40\text{mH}$

Answer 1

The correct option is C $30\text{mH}$

We know that, for a series combination of inductors such that their magnetic fields aid each other, net inductance is given by,

$L_{eq}=L_1+L_2+2M$

$\Rightarrow L_{eq}=10+10+2\times 5$

$\Rightarrow L_{eq}=30\text{mH}$