Question

A tightly wound coil has \(100\) turns, radius \(10\,\text{cm}\), and carries \(1\,\text{A}\). What is its magnetic field at the centre?

Options

• \(3.14\times10^{-4}\,\text{T}\)

• \(6.28\times10^{-3}\,\text{T}\)

• \(6.28\times10^{-4}\,\text{T}\)

• \(6.28\times10^{-6}\,\text{T}\)

Answer 1

Use \(B_0=\frac{\mu_0NI}{2R}\), with \(N=100\), \(I=1\,\text{A}\), and \(R=0.1\,\text{m}\). Substitution gives \(B_0=6.28\times10^{-4}\,\text{T}\).