Question

The current flowing through an ac circuit is given by $i=5\sin \left(120\pi t\right)A$
How long will the current take to reach the peak value starting from zero?

Answer 1

From given equation:
$\omega =120\pi$
$\Rightarrow T=\frac{1}{60}\sec$
The current will take its peak value in $\frac{T}{4}$ time
So $t=\frac{T}{4}$$=\frac{1}{240}s$