The current $i$ in a coil varies with time as shown in the figure. The variation of induced emf with time…
The current $i$ in a coil varies with time as shown in the figure. The variation of induced emf with time would be
Solution
We know
$e=-L \frac{d i}{d t}$
During 0 to $\frac{T}{4}, \frac{d i}{d t}=$ constant
So, $\quad e=-$ ve
For $\quad \frac{T}{4}$ to $\frac{T}{2}, \frac{d i}{d t}=0$
$e=0$
For $\frac{T}{2}$ to $\frac{3 T}{4}, \frac{d i}{d t}=$ constant
$e=+ \text { ve }$
