EM Spear -- Large rolling model of an electromagnetic wave shows the relation between electric and magnetic field vectors in a “photon”

Hertzian Waves -- classic spark transmitter has two large resonant circuits (jar capacitor and resistance) tuned to the same frequency - transmitter circuit is powered by a spark coil, receiver picks up Hertzian waves emitted and lights a neon bulb. Receiver can be “detuned” to show decreased efficiency.

Cenco 3-meter Transmitter -- small tube-style transmitter sends radio waves to a pickup antenna, lighting a small bulb in the center of the antenna. Moving the antenna away from the transmitter dims the bulb, and rotating the antenna at right angles extinguishes the bulb, showing the polarized nature of the radio waves.

Tesla Coil (Corona Discharge) -- high voltage AC current at 350 kHz produces intense corona discharge from sharp points attached to electrodes.

Tesla Coil and Fluorescent Tube -- EM waves from Tesla coil will light a fluorescent tube held at a distance. “Tuning” the output of the Tesla coil to the resonant frequency of the bulb will increase the brightness of the bulb even though the voltage output of the coil is decreased.

Radio and Charging Rod -- A plastic rod is charged by rubbing it vigorously with a wool cloth. The small discharges between the rod and the cloth give off electromagnetic noise that can be picked up on an AM radio.

Infrared in Spectrum with Thermopile (Planck Curve) -- light from a hot carbon arc is spread into a spectrum, then various portions of the spectrum are scanned with a thermopile. It is shown that the greatest amount of energy is in the infrared portion of the spectrum where no visible light exists, then tapers off into the visible and disappears in the ultraviolet. A new thermopile that drives a vertical LED display can be used to map out the emission curve for the carbon arc (make sure to ask for it specificallyif you want it; the setup is different than the original)

Ultraviolet in Spectrum -- light from an arc lamp is spread into a spectrum, and a fluorescent sheet placed beyond the violet end of the spectrum fluoresces where no visible light exists.

MICROWAVE SET -- A microwave emitter and receiver are mounted on a vertical circular board. The emitter is stationary, while the receiver is free to rotate with the board. A bar-graph display mounted on the board shows the intensity of the microwave signal picked up by the receiver as it is moved around. Effects that can be shown include:

Straight Line Propagation Reflection from Flat Surfaces Refraction Absorption by Water Single-Slit Diffraction Double Slit Interference Multiple-Slit Interference Waveguide

Interferometer Polarization Bragg Scattering Standing Waves in Cavity Total Internal Reflection Barrier Penetration (Tunnelling) Quarter-Wave Plate

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