Radio waves for Communication
Radio waves are electromagnetic waves with wavelengths larger than the infrared light. Like all other electromagnetic waves, they travel at the speed of light. The wavelengths can vary from the size of a football field to the size of a football. They can be produced naturally by large stars and by lightning. Man-made radio waves are used for transmitting signals and currents. Specific Properties of Radio Frequency (RF) Current
Radio frequency is the frequency of radio waves ranging from 3 kHz to 300 GHz. RF current has the following properties: 1. The energy in an RF current can emit back into space in the form of radio waves. This is the foundation of radio technology. 2. RF current does not penetrate deeply into conductors but flows along the exterior. This is known as skin effect. Due to this, the body gets burnt only on the surface on coming in contact with RF currents. These burns are called RF burns. 3. RF currents do not easily give electric shocks because they change direction too quickly to cause the depolarization of nerves membranes. 4. RF currents can easily ionize air to create a conductive path through it. 5. RF current has the ability to appear to flow through an insulating substance. 6. RF current has a tendency to reflect from discontinuities in the cable and travel back down the cable toward the source when conducted in an ordinary electric cable, causing a condition called standing waves. Because of this, RF current must be carried in specialized cables called transmission lines. FM: It stands for frequency modulation. The radio wave has a variable frequency and the technique makes radio reception fairly free from static interference has become the most favored transmission method as a result. Radio Spectrum
Radio spectrum refers to the part of the electromagnetic spectrum reserved for radio waves. They have a wavelength greater than infrared light which has a wavelength of 10-4 m. Radio Bands
A radio band...
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