The radius ' $r$ ' of a wire is given by $r=\sqrt{\frac{64 \mathrm{LA}}{\pi \mathrm{Bv}}}$, where $\mathrm{I}$ is electric current, $\mathrm{B}$ is magnetic field and ' $v$ ' is velocity. Then the parameter A in the formula represents ____.

• A

  Resistance
• Correct answer
  B

  Resistivity
• C

  Capacitance
• D

  Conductivity

Hence, the correct answer is option: 'B'.