Can’t get enough of hands-on electromagnetic experiments? We have some more ideas for you to try:
What is the magnetic power of a single coil wrapped around a nail? Of 10 turns of wire? Of 100 turns? Experiment with different numbers of turns and see what happens. One way to measure and compare a magnet’s “strength” is to see how many staples it can pick up.
What is the difference between an iron and an aluminum core for the magnet? For example, roll up some aluminum foil tightly and use it as the core for your magnet in place of the nail. What happens? What if you use a plastic core, like a pen?
What about solenoids? A solenoid, you remember, is another form of electromagnet. It’s an electromagnetic tube generally used to move a piece of metal linearly. Find a drinking straw or an old pen (remove the ink tube). Also find a small nail (or a straightened paper clip) that will slide inside the tube easily. Wrap 100 turns of wire around the tube. Place the nail or paper clip at one end of the coil and then connect the coil to the battery. Notice how the nail moves? Solenoids are used in all sorts of places, especially locks. If your car has power locks, they may operate using a solenoid. Another common thing to do with a solenoid is to replace the nail with a thin, cylindrical permanent magnet. Then you can move the magnet in and out by changing the direction of the magnetic field in the solenoid. (Please be careful if you try placing a magnet in your solenoid, as the magnet can shoot out.) Electromagnetic Experiments
How do I know there’s really a magnetic field? You can look at a wire’s magnetic field using iron filings. Buy some iron filings, or find your own iron filings by running a magnet through playground or beach sand. Put a light dusting of filings on a sheet of paper and place the paper over a magnet. Tap the paper lightly and the filings will align with the magnetic field, letting you see its shape!
How is an electromagnet made?
You can make a simple electromagnet yourself using materials you probably have sitting around the house. A conductive wire, usually insulated copper, is wound around a metal rod. The wire will get hot to the touch, which is why insulation is important. The rod on which the wire is wrapped is called a solenoid, and the resulting magnetic field radiates away from this point. The strength of the magnet is directly related to the number of times the wire coils around the rod. For a stronger magnetic field, the wire should be more tightly wrapped.
What is an electromagnet and how does it work?
Electromagnets create a magnetic field through the application of electricity. When you introduce the current, either from a battery or another source of electricity, it flows through the wire. This creates a magnetic field around the coiled wire, magnetizing the metal as if it were a permanent magnet. Electromagnets are useful because you can turn the magnet on and off by completing or interrupting the circuit, respectively.
What are the main characteristics of electromagnets?
One key feature is that an electromagnet has a magnetic field, but only when the electric current is flowing. They’re used in situations where regular magnets wouldn’t make any sense.