is a combination of a prefix " tele "
whuch means " at a distance
" and the word " vision
" whuch means " seeing
", hence, "television" implies " seeing at a distance
". it is one field of electronic technology from whuch people around the world benefited much. It''s concept has been developed in the 1920''s but commercial application began near 1940''s. The recent entry to the technology is the development of digital TV system whuch is becoming popular among household.
The words means the transmission and reception of moving visible images so that at a distant receive the likeness of original scnece can be viewed.
There are three basic broadcasting system in the world, they are (a) National Television Sytem Committee
) which is use in Japan, Philippines, North America and Latin America (b) Phase alteration by line
) which is use in Unioted Kingdom, Western Europe, South Africa, New Zealand and Australia: and (c) Sequential Chrominance and Memory (SECAM
) which is use in France, Eastern Europe and USSR. NTSC are considered an American System while PAL and SECAM are european system.
There is little difference between a television reciever and radio reciever.
In radio reciever
,the sound is first converted to an electrical signal which is transmitted to a distant point. The signal then Converted by a speaker into mechanical motion,producing audible sound waves
,light and sound signals are converted and transmitted to a distant point. Both signals are received and converted back to light and sound by the television set.
Television and Radio signal are transmitted through space by means of electromagnetic waves
more commonly known as RF (Radio Frequency)