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The Electricity & Magnetism Light Bulb Demo Will Light Up Minds

Posted on April 24, 2012 by Buzz Putnam There have been 5 comment(s)

The link between electricity and magnetism finds its legendary roots back to Hans Christian Orsted when he supposedly found that electric current affected his compasses during a student lecture.  That piece of scientific history may be one of exaggerated legend, but the marriage of electricity with magnetism has been widely known for over a century, later to be given a full mathematical explanation by Lord Kelvin and James Clerk Maxwell.  The concept of electron movement causing the production of an ensuing magnetic field is a fundamental model used in describing electromagnets, generators, transformers and electric motors.



Can't view this in YouTube? Try watching in Vimeo.

Students can witness the magnetic fields produced by electron movement using compass deflections and observe first-hand the mechanical spin of a solenoid in an electric motor.  Using the “Electricity & Magnetism Light Bulb Demo”, you will demonstrate to your students the relationship between electricity and magnetism in an amazing and unconventional way, using a Victorian light bulb under conditions not normally observed in everyday life. When a wire that carries an electrical current is placed within a magnetic field, each of the moving charges, which comprise the current, experience the Lorentz force and together they can create a macroscopic force on the wire.  The following equation, in the case of a straight, stationary wire is as follows:

F=IL x B

 …where is a vector whose magnitude is the length of wire, conventional current flow I, B is the Magnetic Flux Density and F is the force on the wire.

The Electricity & Magnetism Light Bulb Demo can clarify several important concepts:

1.   Using DC (Direct Current), electrons flow through a bulb’s filament in one direction.

2.   Using AC (Alternating Current), electrons flow through a bulb’s filament in two directions.

3.   A magnetic field is produced when electrons flow through a conductor.

4.   When magnets are placed near wires that carry electric current, a force is exerted on the wire. (Technically, the force is on the electrons in the wire.  The electrons are “trapped” in the wire therefore causing the wire to move instead of the individual electrons.)

5.   When a wire carrying an electrical current is placed in a magnetic field, each of the moving charges (electrons), which comprise the current, experiences the Lorentz force and together they can create a macroscopic force on the wire itself.

Acknowledgements:

Thank you to Buzz Putnam, Physics Teacher and Whitesboro High School Science Department Chairman, for his development of this product and his assistance in writing these instructions.

Items to create your own demo:

 

Electricity & Magnetism Light Bulb Demo

Electricity & Magnetism Light Bulb Demo

Product # P6-4000

$49.00

The Electricity and Magnetism Light Bulb demo featured in the video.  Does not include Neodymium magnet (See below).
Pair of Neodymium Magnets

Pair of Neodymium Magnets

Product # P8-1123

$15.00

This 3/4" neodymium-iron-boron cylinder packs serious power in a small package.
Replacement Bulb for P6-4000

Replacement Bulb for P6-4000

Product # P6-4000-05

$13.95

Hand made Victorian light bulb, replica of Thomas Edison's original design, 60W, carbon filament.

This post was posted in CoolStuff Newsletters, Electricity, Magnetism

5 Responses to The Electricity & Magnetism Light Bulb Demo Will Light Up Minds

  • So for $84 I can get a single copy of an apparatus that has only one use. But I can have the students demonstrate the same thing for themselves with a flashlight battery, a few wires, a ferrite ("refrigerator") magnet, and a piece of aluminum foil. Since the battery, wires, and magnet have other uses, the cost is for the foil -- less than a penny per student.

    Posted on April 25, 2012 at 11:24 pm

  • Judging from the large number of orders we’ve received for this new demo, a lot of other teachers disagree with you.

    Posted on April 27, 2012 at 7:23 am

  • I'm in the UK - while I can do the AC part easily enough (we have some old carbon filament lamps for optics) and did so after seeing this, we don't have a suitable high-voltage high-current power supply for the DC part. Any chance of a 240V version? It would either need to use UK bayonet fitting 240v lamps or come with a supply of US lamps, of course.

    Posted on November 30, 2012 at 6:51 am

  • Our Customer Service department is checking into this. Thanks for your interest.

    Posted on December 4, 2012 at 10:46 am

  • We do not currently have a 240V bulb demo available. We suggest to purchase a voltage converter from a local electronics store by you. They are relatively inexpensive and can change US voltage to UK voltage in a flash.

    Posted on December 4, 2012 at 11:28 am

Comments