Question

A circular coil of radius $10cm$ and $25$ turns is rotated about its vertical diameter with an angular speed of $40rad$ $s^{-1}$ in a uniform horizontal magnetic field of magnitude $5\times {10}^{-2}T$. Calculate the emf induced in the coil. Also, find the current in the coil if the resistance of the coil is $15\Omega$.

Answer 1

$r=10cm=10\times {10}^{-2}m$

$N=25$

$\omega =40rad{s}^{-1}$

$B=5\times {10}^{-2}T$

${\epsilon }_0=NBA\omega =25(5\times {10}^{-2})\times [3.14\times {(10\times {10}^{-2})}^2]\times 40=1.57V$
$I=\frac{{\epsilon }_0}{R}=\frac{1.57}{15}=0.1047A(I=\frac{{\epsilon }_0}{R})$