Answer:
the resistivity of the wire is 1.70 x 10^-7 Ωm.
Step-by-step explanation:
The resistivity of a wire can be calculated using the formula:
ρ = (RA)/L
where ρ is the resistivity of the wire, R is the resistance of the wire, A is the cross-sectional area of the wire, and L is the length of the wire.
To find the cross-sectional area of the wire, we first need to calculate the radius:
r = d/2 = 0.91 mm / 2 = 0.455 mm = 4.55 x 10^-4 m
where d is the diameter of the wire.
The cross-sectional area is then:
A = πr^2 = π(4.55 x 10^-4 m)^2 = 6.53 x 10^-7 m^2
Now we can plug in the values for R, A, and L:
ρ = (RA)/L = (70 mΩ x 6.53 x 10^-7 m^2) / 2.7 m = 1.70 x 10^-7 Ωm
Therefore, the resistivity of the wire is 1.70 x 10^-7 Ωm.