Moving Charges And Magnetism

Two concentric coplanar circular loops of radii '\(r{ }_1\)' and '\(r_2\)' respectively carry currents '\(i_1\)' and '\(\mathrm{i}_2\)' in opposite directions (one clockwise and other anticlockwise). The magnetic induction at the centre of the loops is half that due to '\(i_1\)' alone at the centre. If \(r_2=2 r_1\), the value of \(\frac{i_2}{i_1}\)