Question

If emf induced in a coil is $2V$ by changing the current in it from $8A$ to $6A$ in $2\times {10}^{-3}s$, then the coefficient of self induction is

• A. $2\times {10}^{-3}H$
• B. ${10}^{-3}H$
• C. $0.5\times {10}^{-3}H$
• D. $4\times {10}^{-3}H$

Answer 1

The correct option is A $2\times {10}^{-3}H$

Induced emf $e=2V$

$i_1=8A,i_2=6A$

$△t=2\times {10}^{-3}s$

Coefficient of self induction

$L=\frac{e}{△i/△t}=\frac{-2}{(6-8)/2\times {10}^{-3}}$

$=\frac{-2\times 2\times {10}^{-3}}{-2}$

$=2\times {10}^{-3}H$