Question

The current $i$ in a coil varies with time $t$ according to the graph shown below. Which of the following graphs, shows the induced emf $\left(E\right)$ in the coil with time?



$[$0.77 Mark$]$

• A.
• B.
• C.
• D.

Answer 1

The correct option is C


We know that, induced EMF,

$E=-L\frac{di}{dt}$

For $AB$, $\frac{di}{dt}=0\Rightarrow E_{AB}=0$

For $BC$, $\frac{di}{dt}=-ve$ and constant

$\Rightarrow E_{BC}=+ve$ and constant

For $CD$, $\frac{di}{dt}=+ve$ and constant $\Rightarrow E_{CD}=-ve$ and constant

Hence, the correct graph of induced emf $\left(E\right)$ in the coil with time is,


Therefore, option $\left(C\right)$ is the correct answer.