Question

Calculate the resistance in milliOhms of a copper wire 0.535 m long and 0.02 m diameter? The resistivity of copper is 1.7 x 10^-8.

Answer 1

R = resistitivity x lenght / area

Lenght = 0.535 m

Area = pi r ^2 = pi (0.02)^2 = 1.26x10^-3 m^2

resitivity of copper = 1.7 x10^-8 ohm meter

Replacing:

R = 1.7 x10^-8 x 0.535 / 1.26x10^-3 = 7.21 x 10^-6 ohm