Question

In an inductor, the current $I$ varies with time $t$ as $I=5 A+16( A / s ) t$. If induced emf in the inductor is $5 \,mV$, the self inductance of the inductor is

• A. $3.75 \times 10^{-3} H$
• B. $3.75 \times 10^{-4} H$
• C. $3.125 \times 10^{-3} H$
• D. $3.125 \times 10^{-4} H$

Answer 1

Answer: (D)

$I=5+16 t $
$\Rightarrow \frac{d i}{d t}=16 $
$\varepsilon=5 \times 10^{-3} V $
$|\varepsilon|=\frac{L d i}{d t}=L(16)=5 \times 10^{-3}$
So, $L=3.125 \times 10^{-4} H$