MAGNETIC BEHAVIOUR OF A CURENT CARRYING SOLENOID

A solenoid is a long helix having a large number of close turns of insulated copper wire wound over a tube or china-clay. When an electric current is passed through the solenoid, it behaves like a bar magnet.

its verified by:

1. A current-carrying solenoid suspended freely always rests in a definite direction.

If we place a solenoid in a brass hook and suspend it by along thread so that it can move freely in a horizontal plane, we find that it always rest in the north-south direction. The end of the solenoid pointing north is called the north pole and the end of the solenoid pointing south is called south pole.

2. Two current-carrying solenoids exhibit mutual attraction and repulsion.

If we suspend a solenoid in a brass-hook by means of a thread and bring one by one the end of another solenoid close to one end of the suspended solenoid, we observe that when the south pole of the second solenoid brought near the north pole of the suspended solenoid, the suspended solenoid comes closer, but when the north pole is brought near the north pole, the suspended solenoid moves away. This shows that the unlike poles of the two solenoids attract each other and like poles repel each other.

The above observation shows that a current-carrying solenoid is just like a bar-magnet, having north pole and south pole.

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                                                                                                                   praveen

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