Question

The resistance of a wire 2.5 m long and 0.9 mm in diameter is 0.07 ohm. What is the resistivity of the material of the wire?

Answer 1

R = 2.5 m
L = 0.9 mm
D = 0.07 ohm
r = 0.07 / 2 ohm

R = rho 1/A
rho = RA /L
rho = R pie r^2 / L

resistivity = 77 / 80

hope answer will be correct ...if there is any mistake plz tell me

Answer 2

i get the answer as 0.178038 × 10^-7 ohm- metre.