Question

A coil of area $100\, cm ^{2}$ has $500$ turns. Magnetic field of $0.1$ weber/metre $^{2}$ is perpendicular to the coil. The field is reduced to zero in $0.1$ second. The induced e.m.f. in the coil is

• A. 1 V
• B. 5 V
• C. 50 V
• D. Zero

Answer 1

Answer: (B)

$e=-\frac{N\left(B_{2}-B_{1}\right) A \cos \theta}{\Delta t}$
$=-\frac{500 \times(0-0.1) \times 100 \times 10^{-4} \cos 0^{\circ}}{0.1}=5\, V$