Neco 2023 Physics Question 28

A long straight wire carries a current \(I_{1}=5\,\text{A}\). A second parallel wire of length \(0.80\,\text{m}\) is placed \(0.04\,\text{m}\) away and carries an unknown current \(I_{2}\). The magnetic force between the two wires is measured to be \(1.6\times10^{-3}\,\text{N}\) (attractive).\n(a) Determine the magnitude of \(I_{2}\).\n(b) A rectangular coil of \(N=50\) turns, each side \(0.20\,\text{m}\), is placed at the same distance from the first wire so that the magnetic field at the centre of the coil is the field produced by the first wire. If the coil carries a current of \(2\,\text{A}\) and its plane is perpendicular to the field, calculate the torque on the coil.