Physics resistance question?

Question

the diameter of 0 guage copper wire is 8.252 mm. Find the resistance of a 1.00 km length of such wire used for power transmission.

Answer 1

The equation needed is R = (p) x [L/A], where R is resistance, p is the proportionality constant of the material (which is given in a table or your book, in this case for copper), L is length, and A is area.

You have:

p = 1.72x10^-8

L = 1000m (converted to meters)

diameter = 8.252 mm = .004126m

A = pi*r^2 => pi*(.004126)^2 = 5.35 x 10^-5

Now, solver for R:

R = (1.72x10^-8)[(1000)/(5.35x10^-5)]

R = 0.32 Ohms