Question

The shown graph is the curve between magnetic field $\left(B\right)$ and time $\left(t\right)$. The magnetic field exists throughout the plane of a conducting loop, perpendicular to the plane of the loop. The induced emf in the loop is maximum during which of the following time interval?

• A. $a-b$
• B. $b-c$
• C. $c-d$
• D. $d-e$

Answer 1

The correct option is A $a-b$


Emf is induced in a loop when magnetic field is varying with time and is given by,

$E=\left|\begin{array}{c}A\frac{dB}{dt}\end{array}\right|$

$\Rightarrow E\propto \left|\begin{array}{c}\frac{dB}{dt}\end{array}\right|$

Or,

Emf induced in the loop is directly proportional to the slope of $B-t$ graph.

In the given graph, slope is maximum during the time-interval $a-b$, thus, induced emf will be maximum in this time-interval.

Hence, option $\left(A\right)$ is the correct answer.