Question

A voltage source having the Laplace transform $\frac{s^2+3s+2}{2s^2+6s+5}$ is applied across a 2 H inductor having zero intial current. The current in the inductor at $t=\infty$ is ___ A. (Answer upto two decimal places)

• A. 0.2

Answer 1

The correct option is A 0.2
$I\left(s\right)=\frac{V\left(s\right)}{Ls}=\frac{s^2+3s+2}{2s(2s^2+6s+5)}$

Final value = $\underset{s\to 0}{\overset{Lt}{\to }}s.I\left(s\right)$

$\underset{s\to 0}{\overset{Lt}{\to }}\frac{s^2+3s+2}{2(2s^2+6s+5)}=\frac{2}{2\times 5}=\frac{1}{5}=0.2A$