Question

A rectangular coil of $100$ turns and size $0.1 \times 0.05\, m$ is placed perpendicular to a magnetic field of $0.1\, T$. The induced emf when the field drops to $0.05\, T$ in $0.05\, s$ is

• A. 0.5 V
• B. 1.0 V
• C. 1.5 V
• D. 2.0 V

Answer 1

Answer: (A)

0.5 V

Answer 2

The induced emf
$e=-N \frac{\Delta \phi}{\Delta t}$
or $e=-\frac{N\left(B_{2}-B_{1}\right) A}{\Delta t}$
or $e =-\frac{100(0.1-0.05) \times 0.1 \times 0.05}{0.05}$
$e =0.5\, V$