Science Projects And Inventions

YOU NEED :

• Some insulated copper wire
• A three inch nail
• A 9 volt battery
• Some small nails
• A piece of cardboard
• Two needles
• A bar magnet
• A cork
• A bowl of water

Make an electromagnet by winding some insulated i pin wire all along the length of a three inch nail without overlapping the wire. Strip and connect the two ends of the  wire to the positive and negative terminals of a 9 volt battery. If you bring a few paper clips and other metallic objects close to the nail you will see that they stick to the nail and can even be picked up with it. This . happens because a magnetic force is created  from one end of the coi1 to the other end as electricity flows  through the wire. This force lines up the magnetic particles in the nail thus turning it into a magnet. This is what  is  referred  to  in  Faraday's  laws of Electromagnetic Induction.

A SIMPLE COMPASS

Stick a needle on a cardboard and rub it approximately 60 times with one end of a magnet. Ensure the same end is rubbed on the needle each time. This develops a little magnetism to the needle. Pick up another needle with the first needle to test it. Insert the magnetised needle through a cork. Take a bowl of water and float the cork in it. On a sheet of card, draw a compass showing north on top, east and west on right and left side respectively, and south on the bottom. Place the bowl of water on the middle of the compass card ensuring the needle is pointing towards north and south. Check its correctness with another compass or Sun. In the middle of the day the Sun is so located that the shadow falls to the north, which is the direction your the needle should point.