Question

The resistance of a 0.29 m long piece of wire is measured to be 0.31 Ohms. The wire has a cross-sectional area of 0.003 m2. What is the resistivity of the wire?

Answer 1

3.21×10⁻³ Ωm

Step-by-step explanation:

Applying,

R = Lρ/A................... Equation 1

Where R = Resistance of the wire, L = Length of the wire, ρ = Resistivity of the wire, A = cross sectional area of the wire.

Make ρ the subject of the equation

ρ = RA/L................... Equation 2

Given: R = 0.31 Ohms, A = 0.003 m², L = 0.29 m

Substitute into equation 2.

ρ = 0.31(0.003)/0.29

ρ = 3.21×10⁻³ Ωm