Question

The current in a coil is changed from $5A$ to $10A$ in ${10}^{-2}s$. An emf of $50mV$ is induced in coil near it. The mutual inductance of the two coils is

• A. $100\mu H$
• B. $200\mu H$
• C. $300\mu H$
• D. $400\mu H$

Answer 1

The correct option is A $100\mu H$

$emf=M\frac{di}{dt}$
$M=\frac{emf}{\left(\frac{di}{dt}\right)}$
$M=\frac{50\times {10}^{-3}}{\left(\frac{5}{{10}^{-2}}\right)}$
= $100\times {10}^{-6}H$
= $100\mu H$