A 2A current carrying straight metal wire of resistance $1 \Omega$, resistivity $2 \times 10^{-6} \Omega \mathrm{m}$, area of cross-section $10 \mathrm{~mm}^2$ and mass $500 \mathrm{~g}$ is suspended horizontally in mid air by applying a uniform magnetic field $\vec{B}$. The magnitude of B is $\underline{\hspace{2cm}}\times 10^{-1} \mathrm{~T}$(given, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2$).