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Al Tobias (wat4y) - Office: Rm. 201, (434) 924-0538 - Lab: Rm. 202, (434) 924-6800

Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography

PLEASE REQUEST DEMOS WELL IN ADVANCE

Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.

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Mechanics
Fluid Mechanics
Oscillations And Waves
Thermodynamics
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Optics
Modern Physics
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Electrostatics
Electric Fields And Potential
Capacitance
Current and Resistance
Electromotive Force And Current
DC Circuits
Magnetic Materials
Magnetism: Magnet collection; video - Magnetic Fields w/ Iron Filings; video - Magnetic Fields w/ Matrix of Iron Rods; video - Magnetic Fields Associated with Current Carrying Wires 1; video - Magnetic Fields Associated with Current Carrying Wires 2; video - Solenoid w/ Iron core; video - Magnetic Deflection of an Electron Beam; video - e/m Tube Lorentz Force Demonstrator; Magnetohydrodynamic Motor; video - Forces Between Current Carrying Wires; video - Vibrating Lamp Filament; video - Force on a Current Carrying Wire in a Magnetic Field; Hall Effect; video - Galvanometer Movement
Inductance
Induction
Complex Circuits
Semiconductors And Tubes
Transmission Lines and Antennas

Magnetohydrodynamic Motor

Purpose:

To demonstrate magnetohydrodynamic forces.

Procedure:

A glass bowl with two parallel electrodes is filled with salt water, just enough to cover the electrodes. A DC power supply is connected to the electrodes. A neodymium disc magnet is placed under the bowl and centered with the electrodes which provides a vertical magnetic field. Applying 8 to 12V to the electrodes will cause water to stream between them. The water's motion can be made more apparent with saw dust, lycopodium powder or a drop of dye.

Hints:

Flip the magnet or reverse polarity of the electrodes to reverse direction of the flow.