Electricity and Magnetism

5N 10.30 - Antennas

Demonstrates: An oscillating electric dipole.
Description: Two antennas are hooked up to an oscilloscope and/or speaker. When the antennas are in phase there will be a signal/sound on the scope/speaker. If they are out of phase no signal/sound can be seen/heard on the scope/speaker. The oscilliscope image can be projected.

5N 10.30a - EM Waves - Propagation & Polarization

Demonstrates: Propagation and polarization in EM waves.
Description: The signal generator puts out a 433.92 MHz UHF frequency (69 cm) which is radiated via a half-wavelength dipole. A small light bulb is connected to a half-wavelength dipole to illustrate received power. The receiver can be picked up and moved around to show the falloff in power with distance, and the radiated beam pattern. The receiver can also be rotated 90 degrees to show how the radiation is polarized. Various wire grids and solid plates (metal, glass, plastic) can be inserted between the transmitter and receiver. And there is a dipole inside a water tank which can be used to show the change in wavelength when an EM wave is made to propagate through water. Good predictive demo.
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5N 20.20 - Induction Coil

Demonstrates: High voltage discharges.
Description: It arcs and sparks.

5N 20.25 - Small Tesla Coil

Demonstrates: Inductance.
Description: A high-voltage generator that uses inductance to light the bulb.

5N 20.30 - Large Tesla Coil

Demonstrates: PURPOSE: To demonstrate a tesla coil, including how magnetic induction and a resonant RLC circuit is used in the production of high-voltage high-frequency sparks.
Description: Our Tesla coil uses a 5000 volt transformer to charge a large oil capacitor. When the potential across the capacitor reaches the breakdown potential of the spark gap, breakdown across the gap occurs. The spark gap then becomes a conducting part of the RLC circuit, which resonates at a frequency of about 200 kilohertz. The large coil in the resonant circuit is the primary of the final transformer and the very fine coil is the secondary, producing about 200,000 volts at 200 kilohertz.

5N 30.10 - 3 cm Microwave Apparatus

Demonstrates: Electromagnetic propagation of microwaves.
Description: Hold dipole array at 90o angle to show polarization. Double and single slits are available for diffraction - swing receiver in an arc ~ 2 meters from slits. An aluminum sheet can be used to show shielding. Interference beats occur when sheet is held parallel to the center line between the transmitter and receiver.