Question

You have a lump of copper with a mass of 1.8 grams. Copper is ductile so you can draw it into a cylindrical wire. You draw it into a wire with length L and diameter D so that it has a resistance of 2Ω.

What is the length of the wire in m and the diameter in mm?

Hint: you may need to look up some properties of copper!

Answer 1

Given me 1199 R=22 D&copper = 8.96g/cm², Resistivity of - 1.68x108 am Volume - We know, Density = = mass Voluone of copper (v) = m. Dcopper v=r89 =0-2016 m3 9-969/cm? V = 2x107 m3 Crossectional area 't' and length l. So, Al= 2x07 m3 A = 2x107 m2 2 Resistance, is given by Rage 32= (1.68x108) e A A = 8.4x109 xl from @ 1o we get 2x107 = 8.4 x 109 xl a => e = 23.809 - 1 = 4.9 m equating in egrations , # D² = 8.4 x 109 x 4.9 4 4x8.4x109x7.01 2 = 0.0002284 IT → = 0.2299 mm