Question

A copper wire of cross-sectional area 2.0
mm2, resistivity = 1.7x10-8 sm, carries a
current of 1 A. The electric field in the copper
wire is
1) 8.5x10-5V/m 2) 8.5x10-4V/m
3) 8.5x10-v/m 4) 8.5x10-2 V/m​

Answer 1

Answer:

Explanation:

=> cross-sectional area of copper wire, A = 2.0  mm² = 2.0 * 10⁻⁶ m²,

=> resistivity, f = 1.7x10⁻⁸ Ωm,

=> current, I = 1 A.

=> The electric field E in the copper  = ?

R = fl / A = 1.7 * 10⁻⁸ * l / 2 * 10⁻⁶

V = IR = 1 * 1.7 * 10⁻⁸ * l /  2 * 10⁻⁶

E = dV / dL = V/l

= 1.7 * 10⁻⁸ * l / 2 * 10⁻⁶ l = 1.7/2 * 10⁻²

= 0.85 * 10⁻² V/m

= 8.5 * 10⁻³ V/m

Thus,  The electric field in the copper  wire is 8.5 * 10⁻³ V/m