5G20.74 - Magnetic Flux | Instructional Resources and Lecture Demonstrations

Code Number:

5G20.74

Demo Title:

Magnetic Flux

Condition:

Good

Principle:

Magnetic Flux around Magnetic Poles

Area of Study:

Electricity & Magnetism

Disclaimer

Equipment:

Umbrella with ribbon cable, Keithley Electrometer, Butterfly net.

Procedure:

See also 5B20.50 in Electricity and Magnetism.

Set up the Flux unit as shown. Make sure to tighten the leg set screws securely. Place the surround box around the unit if using the fog machine or fog from the can. Chose the desired size white board which can then be place flat or at any angle in the box to cut as few or as many of the field lines as needed.

Point the umbrella toward magnetic north or south. You can also use a dip needle to adjust for the dip angle. When you open the umbrella, the needle on the meter will jump toward the positive as the flux increases. Close the umbrella and the needle goes negative.

The net can be used as a demo for magnetic flux.

References:

Jeff McManus, "Demystifying Electric Flux and Gauss’s Law", TPT, Vol. 55, #4, Apr. 2017, p. 252.
Norihio Sugimento, "Umbrella Coil", TPT, Vol. 46, #7, Oct. 2008, p. 443.
Giuseppe Giuliani, "Electromagnetic Induction: How the "Flux Rule", has Superseded Maxwell's General Law", AJP, Vol. 91, #4, April 2023, p. 278.
Azar Ali, "Model Helps Pupils to Understand Ideas of Magnetic Fields and Flux", Physics Education, Vol. 39, #3, May 2004, p. 236.
W. Bolton, "The Flux Density in and Near a Solenoid", Book 4 - Electricity, Physics Experiments and Projects, 1968, p. 50 - 51.
W. Bolton, "Calibration of a Ballistic Galvanometer as a Fluxmeter", Book 4 - Electricity, Physics Experiments and Projects, 1968, p. 48 - 49.

^{Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist. The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose. The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources. Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks. These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage. Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.}