some basics on Electromagnetism

Introduction

In 1820, Hans Christian Oersted discovered that current carrying conductors produce a magnetic field around them. Later Michael Faraday showed that current can be induced in a conducting coil, when there is relative motion between coil and magnet. Thus electric current has a magnetic effect and changing magnetic fields can induce electricity.

Important properties of magnets

1. Property of attraction:Magnets attracts small pieces of materials like iron, nickel, cobalt. The strength of the magnets are concentrated on the poles.
2. Property of direction: a freely suspended magnet always align itself in the north- south direction. The pole which point towards the geographic north is called the north pole of the magnet. The pole which points towards geographic south is called south pole.
3. Property of induction:A magnet can induce magnetism in substances like softiron, cobalt, nickel etc.

The next part of the lesson will be on Wednesday, 4th November 2009.