Determine the electric and magnetic fields at the surface of a cylindrical conductor with diameter d, length = 10d, and conductivity σ, when there is current I passing through it. Assume a uniform electric field throughout, including at the surface of the conductor.

• A. E = I/(10dσ); B = (μ₀I)/($\pi$d)
• B. E = (Iσ)/(10d); B = I/($\pi$dμ₀)
• C. E = (10dσ)/I ; B = ($\pi$d)/(Iμ₀)
• D. E = I/(10dσ); B = 0