Question

A rectangular coil of $200$ turns and area $100c{m}^2$ is kept perpendicular to a uniform magnetic field of induction $0.25T$. If the field is reversed in direction in $0.01$ second, the average induced emf in the coil is :

• A. ${10}^{6}V$
• B. ${10}^{4}V$
• C. ${10}^{2}V$
• D. zero

Answer 1

Answer: (C)

${10}^{2}V$

$Emf=\frac{\Delta \varphi }{\Delta t}$
= $\frac{2\times B\times A\times n}{t}$
= $\frac{2\times 0.25\times 100\times {10}^{-4}\times 200}{0.01}$
= $100V$
= ${10}^{2}V$