Part
4: Magnetism, Electricity, and Work
Objectives
After participating in the program Electricity and
Magnetism, Part 4, students will be able to:
| · explain that a magnetic field changing with time produces a current in a wire |
| · describe how the current produced in a wire by a moving magnetic field changes direction as the motion changes direction |
| · report that the current produced in a wire by a moving magnetic field will vary in magnitude as the number of coils is varied and if a magnetic core is used |
| · recognize that movement (of a diaphragm of a speaker or the rotor of a motor) can be produced by forcing a current through a coil near a stationary permanent magnet |
| · describe how electric power may be generated by causing a magnet to move near a coil of wire |
Materials
(For each group)
· coil of wire with number of turns labeled on it
· 2 permanent magnets
· magnet wire (24 gauge, about 1 m long)
· sandpaper
· ammeter (-250 mA to + 250 mA is ideal)
· straw
· large iron-containing nail
· small speaker
· 2 electrical leads with alligator clips
· 1 D-cell battery and battery holder
· empty 35 mm film canister (or D-cell battery)
· wooden support (for motor, 8” x 8” x ½” pieces of plywood)
· 2 large paper clips
· needle nose pliers
· tape
(For the teacher)
· one small speaker taken apart to show parts
(For the class)
· hand-cranked generator with LED (Carolina Biological Supply)
Total Activity Time: 1 Hour 30 Minutes
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Disclaimer: Some of the procedures for the activities contained in the lessons have been adapted from various resources listed throughout the module.
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PDF Format |
Word Format |
This
work was supported by the Center on Polymer Interfaces and Macromolecular
Assemblies (CPIMA)
as part of the NSF Materials Science and Engineering Center program under
Grant DMR 9808677
Copyright 1996 - 2003, Leland Stanford Junior University. All rights reserved.