Question

Show That a Moving Magnet Can Create an Electric Current

Make or obtain a coil of lightly insulated copper wire. The coil should have a hole in the center that is large enough to allow a bar magnet to easily pass through the coil.

Make the ends of the wires on the coil bare either by using wire-stripping pliers to strip off the insulation or by using sandpaper to scrape off coating-type insulation.

Use alligator-clip wires to connect the coil to an ammeter or multimeter.

Hold a bar magnet by its north end and slowly pass it through the center of the coil and out the other side. Repeat several times, observing the reading on the meter.

Describe what you would expect to see. What do you conclude?

Answer 1

When a bar magnet is moved through a coil connected to an ammeter or multimeter, an electric current is induced due to a changing magnetic field. This follows Faraday's law of electromagnetic induction. The direction of the current will change with the magnet's motion and the orientation of its poles.

Step-by-step explanation:

To demonstrate how a moving magnet can create an electric current, we follow the experimental steps and principles discovered by Michael Faraday. Once you have connected your coil to an ammeter or multimeter, passing a bar magnet through the coil will generate an electric current. The meter should show a deflection when the magnet is moved through the coil, indicating the presence of an electric current. The direction of the current changes if you reverse the movement of the magnet or its poles.

According to Faraday's law of electromagnetic induction, an electromotive force (emf) is induced in the coil when there is a change in the magnetic field within the loop. This change can be achieved by moving the magnet through the coil or by opening and closing a switch in an electromagnetic experiment like Faraday's. It's important to note that it is the change in the magnetic field, not merely its presence, that induces current.

Therefore, based on Faraday's experiments and principles, one would expect the ammeter to show a current that fluctuates in direction based on the movement of the magnet and the direction of its poles. This demonstrates that a changing magnetic field is key to generating an electric current in a wire loop.