Question

A circular coil of diameter $0.2m$ has tightly wound 100 turns and carries a current of $1A$.What is the value of magnetic field strength at the centre of the coil?

Answer 1

$\begin{array}{c}N=100turns\\ d=0.2m\\ R=\frac{d}{2}=\frac{0.2}{2}=0.1m\\ I=1A\\ B=\left(\frac{{\mu }_{o}I}{2R}\right)N\\ =\frac{4\pi \times {10}^{-7}\times 1}{2\times 0.1}\times 1000\\ =2\pi \times {10}^{-4}Tesla\end{array}$