Question

Coefficient of mutual induction between the primary and secondary of a transformer is 4 H. Secondary is shorted by a resistance 2 $\Omega$. Find charge flow through the resistance if a dc current of 3 ampere is cut off from primary.

Answer 1

6 C

Answer 2

The charge flow ($\Delta q$) through the secondary resistance ($R$) when the primary current changes by $\Delta I_p$ is given by $\Delta q = \frac{M \Delta I_p}{R}$. Given $M=4$ H, $R=2$ $\Omega$, and the change in primary current $\Delta I_p=3$ A (as DC current is cut off), the charge flow is $\Delta q = \frac{4 \times 3}{2} = 6$ C.