What is Oersted’s Experiment?

Oersted’s Experiment, conducted by Hans Christian Oersted in 1820, was a groundbreaking discovery that demonstrated the relationship between electricity and magnetism. It showed that an electric current produces a magnetic field around it.

Oersted’s Experiment Setup

Oersted set up a simple experiment to observe the effect of an electric current on a magnetic compass needle:

1. A wire was placed parallel to a magnetic compass needle.
2. When an electric current was passed through the wire, the compass needle deflected from its original position.
3. The direction of deflection depended on the direction of the current.

Oersted’s Experiment Setup

Oersted’s Observations

Oersted made the following key observations during his experiment:

• When the current was switched on, the compass needle deflected.
• When the current was switched off, the compass needle returned to its original position.
• The direction of deflection reversed when the direction of the current was reversed.
• The deflection was maximum when the wire was placed directly above or below the compass needle.

Conclusion

Oersted concluded that:

• An electric current produces a magnetic field around it.
• The magnetic field is circular around the current-carrying conductor.
• The direction of the magnetic field depends on the direction of the current (given by the Right-Hand Thumb Rule).

Right-Hand Thumb Rule

Significance of Oersted’s Experiment

Oersted’s experiment was significant because:

• It established a direct relationship between electricity and magnetism, leading to the development of electromagnetism.
• It laid the foundation for further discoveries, such as Faraday’s law of electromagnetic induction and Maxwell’s equations.
• It demonstrated that electric currents could produce magnetic effects, which is the basis for many modern technologies like electric motors, generators, and transformers.