Discovery of the Magnetic Effect of Current
The magnetic effect of current was discovered by Oersted, not Faraday, Kirchhoff, or Joule. Here's how this discovery came about:

Oersted's Experiment
- In 1820, Hans Christian Oersted conducted an experiment that led to the discovery of the magnetic effect of current.
- He observed that a compass needle placed near a wire carrying an electric current deflected from its original position.
- This demonstrated that an electric current produces a magnetic field around it.

Significance of the Discovery
- Oersted's discovery was crucial in understanding the relationship between electricity and magnetism.
- It laid the foundation for the development of electromagnetism and led to the creation of electromagnets, electric motors, generators, and other devices.

Key Contributors
- While Oersted discovered the magnetic effect of current, other scientists such as Faraday, Kirchhoff, and Joule made significant contributions to the field of electromagnetism.
- Faraday's work on electromagnetic induction and Kirchhoff's laws of circuit analysis further advanced our understanding of the relationship between electricity and magnetism.
In conclusion, the magnetic effect of current was discovered by Oersted through a landmark experiment that demonstrated the interaction between electric currents and magnetic fields. This discovery paved the way for numerous technological advancements in the field of electromagnetism.