Question

A 6m long wire has diameter 0.5mm. Its resistance is 50ohm. Find the resistivity and conductivity.

Answer 1

Given - Length (L) = 6m

           Diameter (d) = 0.5mm

           Resistance (R) = 50Ω

Radius = d/2 = 0.5/2 = 0.25mm = 0.25 x 10^-3m

Area (A) = πr^2 = (3.14)(0.25 x 10^-3)^2 m^2

             = 0.19625 x 10^-6 m^2

resistance (R) = ρL / A

therefore, ρ = RA/L

                   = 50 x 0.19625 x 10^-6 / 6

                   = 1.635 x 10^-6 Ωm

conductivity (σ) = L / RA

                         = 6 / 50 x 0.19625 x 10^-6

                         = 6 / 9.8125 x 10^-6

                         = 0.611 x 10^6 Ω^-1m^-1

Answer 2

Answer:

Explanation:l=6m

d= .5mm

R= 50ohm

Resistivity = RA/l

= 50×3.14×0.0005×0.0005÷6÷4

=0.0163ohm