What Is Oersted Experiment?

The magnetic effect of current was discovered by H.C. Oersted in 1820. He observed that flow of electric current through a conductor produce a magnetic field around it. The magnetic effect of current can be demonstrated by doing following experiment.

Experiment to Demonstrate the Magnetic Effect of Current

            First of all make a simple electrical circuit by joining a long straight wire with a battery and a plug. Now, take a magnetic compass needle and place the straight wire parallel to and over the compass needle. Then switch on the circuit so that current flows through the wire from south to north directions. Now, you will found that the north pole of compass needle gets deflected towards the west.
But, if the direction of current in the wire is reversed then the north pole of the compass needle gets deflected towards the east.
The direction of deflection of magnetic needle can be easily determined by SNOW rule. According to SNOW rule, when current flows through a conductor from South to North direction and the wire is held over magnetic needle then the north pole of the magnetic needle deflects towards west.