A conducting rod of length l is falling with a velocity v perpendicular to a uniform horizontal magnetic field B. The potential difference between its two ends will be

• A

  2Blv

• B

  Blv

• C

  $\frac{1}{2}\mathrm{Blv}$

• D

  ${\mathrm{B}}^2{\mathrm{l}}^2{\mathrm{v}}^2$