Question

A circular coil of radius $20$cm has $100$ turns wire and it carries a current of $5$A. Find the magnetic induction at a point along, its axis at a distance of $20$cm from the centre of the coil.

Answer 1

Radius of circular coil $R=20cm=0.2m$
Current flowing $I=5A$
Number of turns $N=100$
Magnetic field at a distance $x$ on the axis, $B=\frac{{\mu }_{o}IN{R}^2}{2(R^2+x^2{)}^{3/2}}$
where $x=20cm=0.2m$
$B=\frac{4\pi \times {10}^{-7}\times 5\times 100\times (0.2{)}^2}{2({0.2}^2+{0.2}^2{)}^{3/2}}=5.6\times {10}^{-4}T$