Activity about Electromagnet. What is an electromagnet? How can you made?
- 1m (1 yd.) of 22 gauge insulated copper wire stripped on both ends
- Lantern batter
- large iron nail no longer than 10 cm (4 in.)
- paper clips
1. In an activities 8.9 and 8.10, we learned that when an electric current flows though a wire, a magnetic field is formed around the wire.
2. Coil the wire ten times around the nail. Bring the nail near some copper clips. What happened?
3. Attach one end of the wire to a terminal of the battery. Bring the nail near some paper clips. Touch the other end of the wire to the other terminal of the battery. What happened?
4. Hold the nail above the table and disconnect the wire from o9ne terminal of the battery.
Explain why you think this happened.
The nail will not pick up paper clips until current flows through the coil of wire. When current flows through the coil of wire, a magnetic field is created around the coil and causes the soft iron nail to become a temporary magnet and attract the paper clips. When the electric current is cut off, the nail will lose its magnetism and the clips will fall off.
The nail you use should be no longer than about 10 cm (4 in.), very large, thick nails will sometimes retain their magnetic properties for a longer period of time and will not release the paper clips readily when the current is turned off.