Question

A rectangular coil of $20$ turns and area of cross section $25sq.cm$ has a resistance of $100ohm$. If a magnetic field which is perpendicular to the plane of the coil changes at a rate of $1000teslapersec$, the current in the coil is:

• A. $1amp$
• B. $50amp$
• C. $0.5amp$
• D. $5.0amp$

Answer 1

The correct option is C $0.5amp$

$i=\frac{EMF}{R}$
$=\frac{nA\frac{db}{dt}}{R}$
$=\frac{20\times .0025\times 1000}{100}$
$=0.5A$