Write short notes on (a) microwave (b) X - ray (c ) radio waves (d) visible spectrum

Explanation

(a) Microwave : It is produced by electromagnetic oscillators in electric circuits. The wavelength range is ` 1 xx 10 ^(-3) m ` to ` 3 xx 10 ^(-1) m` and frequency range is ` 3 xx 10 ^(11) Hz ` to ` 1 xx 10 ^(9) Hz`. It obeys laws of reflection and polarization. it is used in radar system for aircraft navigation, speed of the vehicle, microwave oven for cooking and very long distance wireless communication through satellites.
(b) X - ray : it is produced when there is a sudden deceleration of high speed electrons at high - atomic number target, and slso by electronic transitions among the innermost orbits of atoms. the wavelength range is ` 10 ^(-13) m "to " 10 ^(-8) `m and frequency range is ` 3 xx 10^(21) Hz ` to ` 1 xx 10 ^(16) Hz`. X- rays have more penetrating power than ultraviolet radiation. X - rays are used extensively in studying structures of inner atomic electron shells and crystel structures. it is used in detecting fractures, diseased organs, formation of bones and stones, observing the progress of healing bones. further, in a finished metal product, it is used to detect faults cracks flaws and holes.
(c ) Radio Waves : It is produced by oscillators in electric circuits. The wavelength range is ` 1 xx 10^(-1) m ` to ` 1 xx 10 ^(4) m ` and frequency range is ` 3 xx 10 ^(9) Hz ` to ` 3 xx 10^(4) Hz ` . it obeys law of reflection and diffraction. it is used in ratio and television communication systems and also in cellular phones to transmit voice communication in the ultra high frequency band.
(d) Visible Spectru : it is produced by incandescent bodies and also it is radiated by excited atoms in gases. the wavelength rage is ` 4 xx 10 ^(-7) m ` to ` 7 xx 10^(-7) m` and frequency range are ` 7 xx 10^(14) Hz ` to ` 4 xx 10 ^(14) Hz`. It obeys the laws of reflection, refraction , interference, diffraction, polarization, photo - electric effect and photographic action. it can be use to study the structure molecules, arrangement of electrons in external shells of atoms and sensation of our eyes.