Question

Square loop ABCD of area $20c{m}^2$ and resistance $5\Omega$ is rotated in a magnetic field B = 2T through ${180}^{\circ }$, with field perpendicualr to the loop initially. In 0.01 seconds the magnitude of induced e.m.f is …………….

• A. 0.4 V
• B. 0.8 V
• C. 0.6 V
• D. 1.0 V

Answer 1

The correct option is B 0.8 V

$e=\frac{BAN(cos{\theta }_1-cos{\theta }_2)}{t}$
$=\frac{(2\times 20\times {10}^{-4}\times [1-(-1)]}{0.01}$
$=0.8V$