If a metal wire 4m long and cross-sectional area 0.8 mm2 has a resistance of 60, find the resistivity of the wire

Answer Details

The resistivity of a material is a measure of how much it resists the flow of electrical current through it. It is given by the formula:
ρ = RA/L
where ρ is the resistivity, R is the resistance, A is the cross-sectional area of the wire, and L is the length of the wire.
In this problem, we are given the length, cross-sectional area, and resistance of the wire. So we can rearrange the formula to solve for the resistivity:
ρ = RA/L = (R x A)/L
Substituting the given values, we get:
ρ = (60 Ω x π x (0.8 mm)^2) / (4 m)
Simplifying this expression, we get:
ρ = 1.2 x 10^-6 Ω m
Therefore, the resistivity of the wire is 1.2 x 10^-6 Ω m. So the correct option is:
- 1.2x10^-6