Question

Two wires are identical, except that one is aluminum and one is copper. The aluminum wire has a resistance of 0.219Ω. What is the resistance of the copper wire? Take the resistivity of copper to be 1.72 x 10-8 Ω·m, and that of aluminum to be 2.82 x 10-8 Ω·m.

Answer 1

Here, for the aluminium wire

as Resistance = p * Length/Area

for the same length and area

Resitance/resistivity = constant

let the resistance of the copper wire is R

R/0.219 = 1.72 *10^-8/(2.82 *10^-8)

solving for R

R = 0.134 Ω

the resistance of the copper wire is 0.134 Ω