In your own words, explain why the moving compass needle proved there was a magnetic field around the electric current.

The moving compass needle demonstrated the presence of a magnetic field around the electric current due to the principle of electromagnetism. Here's a step-by-step explanation:

1. When an electric current passes through a wire, it generates a magnetic field around it. This is a fundamental principle of electromagnetism.

2. A compass works by aligning its needle with the Earth's natural magnetic field. The needle of a compass is essentially a tiny magnet that is free to rotate and align itself with any magnetic field present.

3. When the compass was brought near the wire carrying the electric current, the needle moved. This movement indicated that the compass needle was aligning with another magnetic field, not just the Earth's.

4. The only other magnetic field present in this scenario was the one generated by the electric current in the wire. Therefore, the movement of the compass needle proved that there was indeed a magnetic field surrounding the electric current.

5. The direction of the needle also gives information about the direction of the magnetic field. This further confirms the presence of the magnetic field around the electric current.

In conclusion, the moving compass needle served as a visual and physical proof of the magnetic field generated by the electric current.