Question

A coil of radius $0.10m$ is made from a long wire $6.28m$ in which a current $1.0A$ is flowing. Calculate the value of magnetic field at its centre.

Answer 1

Length of wire to make coil $=6.28m$
Radius of coil $R=0.10m$
Number turbs $N=\frac{1}{2\pi R}=\frac{6.28}{2\times 3.14\times 0.10}=10$
Current flowing through coil $I=1.0A$
Magnetic field at the centre of coil
$B=\frac{{\mu }_{0}NI}{2R}$
$B=\frac{4\pi \times {10}^{-7}\times 10\times 1.0}{2\times 0.10}$
$B=\frac{4\times 3.14\times {10}^{-5}}{2}$
$=6.28\times {10}^{-5}T$