Science Projects Index

Electromagnets

On a three-inch nail, wind some insulated copper wire. Care should be taken to see that when you wind, they don't overlap. Strip off the ends of the wire and connect them to a 9-volt battery. The nail has now become an electromagnet. If you bring any small iron objects like a nail, paper clip, pin etc., you will find them getting attracted to the electromagnet. This phenomenon is known as Electromagnetic Induction. And the relation between the direction of flow of electricity and the direction of the magnetic forces are dealt with in Faraday's Laws of Electromagnetic Induction.

Magnetic Field

Keep a magnet on a piece of white paper on a table. Pour some iron filings on it. You will find a strange manner in which the filings stick to the poles. And if you keep the magnet under the paper and pour the filing on the paper and then give a slight shake to the paper you will see the filings arrange themselves in definite lines starting from each pole. Some lines would connect to both poles. These lines give an indication of the limits of the magnetic field of that magnet.