Question

Consider a copper wire with circular cross section with radius 0.5 mm, where the conduction electrons in the wire have drift velocity 1 mm/s. Copper has a density of 8960 kg/m3, and copper atoms have a mass of 63.5 amu (where 1 amu = 1.67 x 10−27 kg). (a) How many copper atoms are in one cubic meter of copper wire? (b) Assume each copper atom provides one conduction electron (that is, for each copper atom, one electron is able to flow freely through the metal), how many electrons are in one cubic meter of copper wire? (c). How far does a conduction electron drift in one second? (d). What is the volume of conduction electrons that pass a given point in one second? How many conduction electrons are in this volume? (e) What is the current flowing through the wire?

Answer 1