Monday, 20 October 2014


  1. Suppose that there are 8.5x1028 conduction electrons per m³ of copper. A piece of copper wire has a cross-sectional area of 1 mm². A current of 0.1 A flows through it. How many electrons flow past a point P on the wire in 1 s?
  2. Find the volume of copper that contains this number of electrons. Find the length of the copper wire that contains has the same volume.
  3. Since the conduction electrons in this length of the wire flows past point P in 1 s, find the average velocity of these electrons.
  4. Find the force on this length of wire if a magnetic flux density of 0.1 T is at right angle to it.
  5. Using this force, find the average force on one conduction electron.
  6. Find this force again using F = BQv.