The handheld electromagnet allows students to observe directly the interaction between electricity and magnetism. A wire coil, wound around a steel bolt, is connected to both a battery power source, and a momentary push switch, which activates the electromagnetic effect produced in the coil. Place the electromagnet near a pile of paperclips, while holding down the switch, and it will easily attract and lift quite a few paperclips, powered only by a 1.5 Volt battery.
Advice for using the Electromagnet:
Questions for Students / Items of Interest:
Q1) How is an electromagnet similar to a permanent magnet? Use a compass to find its magnetic poles.
Q2) Try reversing the battery to see what effect this has on the electromagnet.
Q3) What are some other devices that use a wire coil in a circuit? What effect does a wire coil produce?
- A current-carrying loop of wire produces a directional magnetic field (pointed along an axis perpendicular to the plane made by the loop), which is increased when the number of loops is multiplied, making a coil. These coils are used in many applications, including the doorbell and electric motor included with the Petting Zoo, and in many common devices: stereo speakers, automobile starters (solenoid), electrical voltage transformers, and electrical tools, such as a power drill or saw.
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