A cylindrical wire of radius 0 . 5 mm and conductivity 5 × 10 7 S m - 1 is subjected to an electric field of 10 mV m - 1 . The expected value of current in the wire will be x 3 π mA . The value of x is _________.

Step-by-step solution

Conductivity σ = 5 × 10 7   S   m - 1 Radius r = 0 . 5   mm = 5 × 10 - 4   m E = 10 × 10 - 3   V   m - 1 J = σ E = 10 × 10 - 3 × 5 × 10 7 ⇒ J = 5 × 10 5 ⇒ i A = 5 × 10 5 i = 5 × 10 5 × π r 2 = 5 × 10 5 × π × 5 × 10 - 4 2 = 125 π × 10 - 3   A Therefore, i = 125   π   mA Hence, x = 5