Faraday's Experiments on Magnet

 Faraday's Experiment

Faraday's Experiment

Faraday wound a long copper wire, on a cardboard cylinder. Between the turns, he wound twine and between the layers he placed calico-cloth. The ends of the wire were connected to a galvanometer.

Faraday thrust a pole of a bar magnet quickly into the coil. The galvanometer showed the presence of an electric current. He pulled the magnet out of coil. The pointer of the galvanometer deflected, showing the presence of an electric current; but this time the pointer moved in the opposite direction. The amount of deflection was found to increase with the increase in speed of the magnet. He found that when the magnet was at rest inside the coil, no electricity was produced. He repeated the experiment in a different way, moving the coil and keeping the magnet still. The result was the same. Thus, he discovered how magnetism could produce electricity. Relative motion between the conductor and the magnet produces electricity in the conductor.

Activity

i.    Conduct the above experiment by using magnets of different strengths and a coil of insulated copper wire.

ii.   Keep the magnet stationary and move the coil.

iii.  Increase the number of turns of the coil and repeat the experiment.

iv. Observe the deflections for different speeds of the magnet.

Record your observations in all the situations. 
What conclusion can you draw out of your observation?

MICHAEL FARADAY

(1791 – 1867)

Michael Faraday

Faraday was born in a poor blacksmith’s family. He has made remarkable discoveries in both physics and chemistry. He was an assistant to Sir Humphery Davy. In 1831, he liquified chlorine and he discovered banzene in 1825. in 1831, he conducted his experiments on electro-magnetic induction. He has formulated the laws of electrolysis also.
Food for thought

Food for thought

1.Why did Faraday wind twine in between the turns of copper wire?

2.Why did he place calico-cloth in between layers?