Two long parallel wires carry equal current in the same direction. The length of each wire is l and the distance between them is d. Force acting on each wire

• A

  $\frac{{\mathrm{\mu }}_0{\mathrm{i}}^2\mathrm{l}}{2\mathrm{\pi d}}$

• B

  $\frac{{\mathrm{\mu }}_0\mathrm{il}}{2{\mathrm{\pi d}}^2}$

• C

  $\frac{{\mathrm{\mu }}_0{\mathrm{i}}^2{\mathrm{l}}^2}{4{\mathrm{\pi d}}^2}$

• D

  $\frac{{\mathrm{\mu }}_0{\mathrm{i}}^2\mathrm{l}}{4{\mathrm{\pi d}}^2}$