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Radio waves travel in all directions at the speed of light (about 300 OOO km / sec). Upon reaching the receiving antenna, they induce in it an electromotive force (e. m. f), which varies with time as the currents in the transmitting antenna.
The radio is a device whose output has a loudspeaker that converts the electrical signal into sound. The receiver allows for selection of transmission of a radio station with the relevant authorities settings. It occurs all the necessary changes resulting from the antenna. ะต.m. f, causing current to the output of the receiver of a similar nature obtained in the current chain of a microphone or tape recorder. Consequently, the sound vibrations generated by the speaker will sound like variations that have been caught in microphone.
As there are sound waves and waves?
If you call a hammer blow to his cup, then we will hear a sound, but should hold his hand a cup of tone - and the sound stops. Audio is heard only when the wall of the cup ring may vary. Even more clearly you can do this experiment with string instruments. Do we hear the rustling of the grass or the sound of the forest, singing birds and babbling brook, a piercing siren or sweet melodies of music - the sound is always closely connected with the vibration of a body. Sound - a wave propagating in the air. |
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