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

C

Explanation

The induced emf, `e=-L(di)/(dt)`
During 0 to `(T)/(4),(Ti)/(dt)=`constant
So, e=negative
For `(T)/(4)` to `(T)/(2),(di)/(dt)=0`
For `(T)/(2)` to `(3T)/(4),(di)/(dt)=`constant
So, e=positive