The current `i` in a coil varies with time as shown in the figure. The variation of induced emf with time would be

Options

A.
B.
C.
D.

Answer

D

Explanation

We know induced induced emf `e=-L(di)/(dt)`
During `0` to `(T)/(4),(di)/(dt)`=constant
so, induced emf `e=-ve`
for `(T)/(4)` to `(T)/(2),(di)/(dt)=0`
induced emf `e=0`
For `(T)/(2)` to `(3T)/(4),(di)/(dt)`=constant
sol induced emf `e=+ve`