Electromagnetic Induction And Alternating Current Ques 91

  1. The magnitude of the induced electric field in the orbit at any instant of time during the time interval of the magnetic field change is

(a) $\frac{B R}{4}$

(b) $\frac{-B R}{2}$

(c) $B R$

(d) $2 B R$

Show Answer

Answer:

Correct Answer: 91.(b)

Solution:

Formula:

# Fixed loop in a varying magnetic field:

  1. The induced electric field is given by,

$$ \begin{aligned} & \oint \mathbf{E} \cdot \mathbf{d} \mathbf{l}=-\frac{d \varphi}{d t} \text { or } E l=-s \quad \frac{d B}{d t} \\ \therefore \quad E(2 \pi R) & =-\left(\pi R^{2}\right)(B) \text { or } E=-\frac{B R}{2} \end{aligned} $$



Table of Contents