Moving Charges And Magnetism

A long straight wire of length \(2 \mathrm{~m}\) and mass \(250 \mathrm{~g}\) is suspended horizontally in a uniform horizontal magnetic field of \(0.7 \mathrm{~T}\). The amount of current flowing through the wire will be \(\left(\mathrm{g}=9.8 \mathrm{~ms}^{-2}\right)\) :