The Physics of Color Television

A safe place to start is with electromagnetic (EM) field which is generated by charged particles, such as electrons (EP, QP). All electrically charged particles are surrounded by electric fields (Dasgupta ,1994, 104). Charged particles in motion produce magnetic fields. When the velocity of a charged particle changes, an EM field is produced. Electromagnetic fields were first discovered in the 19th century, when physicists noticed that electric arcs (sparks) could be reproduced at a distance, with no connecting wires in between (Petroski, 1993, 31). This led scientists to believe that it was possible to communicate over long distances without wires. The first radio transmitters made use of electric arcs (EP, QP, SP).

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e EM signals that the camera encoded and converts them into scanning rays (EP, QP) through an electron gun at the back of the picture tube. The decoder tells the gun what electronic beams to shoot at the back of the picture tube screen (SP). This is coated with a wide range of mineral and chemical compounds which light up, or glow, when they are activated by the beams from the electron gun (SP, QP, EP, MP). The electron gun sends all its beam messages using the red, green and blue wave lengths because all the shades we see are made of those three wavelengths (BP, QP, EP). Working simultaneously with the electron gun, but independent of it, sound decoding devices in the TV set are translating sound bits to the speaker systems (SP, EP, BP). A standard American TV screen is laid out in a grid of 525 lines, each line composed of phosphorescent dots that glow red, green or blue when struck by electrons shot from one of the TV set's three tubes (EP, QP, SP, BP, MP). The stronger the signal, the brighter the dot. A device called a shadow mask prevents dots from being lit up by the wrong color signal -- which would result in bizarre color shifts (EP, BP, QP). Keeping It Straight Can red signals strike the green phosphorescent do
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Some common words found in the essay are:
EP QP, QP MP, Color Television, SP Radio, QP EP, QP SP, QP Petroski, BP QP, BP MP, BP Colored, ep qp, qp ep, radio waves, electron gun, tv set, petroski 1993, qp ep mp, ep mp, dasgupta 1994, sp qp ep, bp qp, qp sp, radio waves wavelengths, petroski 1993 31, red green blue,
Approximate Word count = 1222
Approximate Pages = 5 (250 words per page)