[PHY] Chapter 14 - Electromagnetic Spectrum

DARRELL ER (COPYRIGHTED) © TOPIC 14: ELECTROMAGNETIC SPECTRUM DARRELL ER (COPYRIGHTED) ©

CHAPTER ANALYSIS THE ABOUT MASTERY EXAM WEIGHTAGE DARRELL ER (COPYRIGHTED) ©

EM WAVES PROPERTIES OF EM WAVES EM WAVE SPECTRUM & APPLICATION KEY CONCEPT DARRELL ER (COPYRIGHTED) ©

PROPERTIES OF EM WAVES - EM waves are transverse waves - Travel at the speed of 3.0×108 in vacuum - Transfer energy from one place to another - Possess wave properties like reflection and refraction - Obey the wave equation, velocity = frequency × wavelength ELECTROMAGNETIC WAVES DARRELL ER (COPYRIGHTED) ©

EM WAVES APPLICATION KEY CONCEPT DARRELL ER (COPYRIGHTED) © Components Application Radio Waves Radio and television communication Microwaves Satellite television and mobile phone networks Microwave oven - microwaves of a particle wavelength are very strongly absorbed by water molecules, heats up the water and cooks food Infrared Radiation Infrared sensors used in thermal imaging equipment Remote control for television Intruder alarm & surveillance systems to detect intruders Visible Light (violent – 380nm, red – 700nm) Laser light - Light Amplification by Stimulated Emission of Radiation Telecommunication through optical fibres using short pulses of light Medical equipment using laser or optic fibre Ultraviolent Ray Main source: sunlight Sun lamps & sun beds Sterilise surgical instruments in UV sterilisation boxes Fluorescent chemicals to coat inside of fluorescent light tubes X-rays Diagnostic tool in medicine and dentistry, to observe the inner parts of one’s body (fractures etc…) Examine flaws and cracks in metal parts joined together Inspect insides of articles such as the insides of luggage Cancer treatment Gamma rays Emitted due to the decay of radioactive nuclei, released during nuclear reactions. Cause serious damage when absorbed by living tissues. Used under controlled conditions to kill cancerous cells and sterilise hospital equipment Check for flaws in metals

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