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these formulas are used. You notice there are now only two formulas, for we already know the value of v; it is 300,000.
     A broadcasting station is radiating a wave whose frequency is 750 kilocycles per second. What is the wavelength of this wave? The first formula gives us the answer; in place of f put the frequency 750 and we get

l = 300,000 / 750 = 400 meters

     Once again, suppose we are receiving signals on our receiv- ing set, which has a wavelength of 300 meters. What is the frequency of the transmitting station? This time use the second formula. Putting 300 for l, we get

f = 300,000 / 300 = 1,000 kilocycles


PRODUCTION OF RADIO WAVES
     In the case of water waves we know very well what caused them. Something dropped into the water caused the disturbance in a similar way Radio waves may be produced. The disturbance, in the case of Radio, is produced in the ether. The only known thing that is capable of affecting the ether (name given to the medium presumed to permeate all matter and space) is the electron and the only way that electrons can produce waves in the ether is by making them move rapidly to-and-fro, so that they vibrate or oscillate. Wires are mostly used to guide the electrons along a given path. These free or moving electrons produce electromagnetic waves in the ether and the motion of the waves produced are similar in every respect to the motion of the electrons within the guiding wires. In order to radiate the Radio waves to great distances, the wire is raised to a high position and it is then called an “aerial” or “antenna.”
     The current from a battery flows steadily and only in one direction through the circuit. That is direct current. There are no back and forth motions in such a circuit. There is, however, another form of electric current known as “alternating current” which does not flow steadily in one direction. Alternating current continually and regularly reverses its direction of flow. There is a period of forward motion followed by a period of reversed motion.

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Webpage©1997, Nostalgia Air
Transcriber  Richard Lancaster