1  INTRODUCTION
Both Electricity and Magnetism have been known for more than 2000
years However, it was only about 200 years ago, in 1820, that it was
realised that they were intimately related During a lecture demonstration
in the summer of 1820, Danish physicist Hans Christian Oersted noticed
that a current in a straight wire caused a noticeable deflection in a nearby
magnetic compass needle He investigated this phenomenon