Question

aluminium wire of radius 0. 25 mm and length of 75 m if the resistance of the wire is 10 Ohm calculate the resistivity of aluminium

Answer 1

Resistance R = ρl/A, where ρ is the resistivity, l the length and A the area of cross section of the wire. ρ = RA/l    = 10 x π x (0.25 x 10-3)2/75 ohm.m    = 0.026 x 10-6 Ω m.    = 2.6 x 10-8 Ω m.