BTEC Applied Science Unit 1 Physics - C Waves in Communication C3 Electromagnetic waves in communication / Btec Applied Science Unit 11 Assignment C Full Assignment

BTEC Applied Science Unit 1 Physics - C Waves in Communication C3 Electromagnetic waves in communication / Btec Applied Science Unit 11 Assignment C Full Assignment What is the electromagnetic spectrum? - ANS-The range of wavelengths or frequencies over which electromagnetic radiation extends. State the order of the electromagnetic spectrum (longest wavelength and lowest frequency -- lowest wavelength and highest frequency). - ANS-Radio waves, microwaves, infrared radiation, visible light, ultraviolet, x-rays, gamma rays Red light has... - ANS-a low frequency and a long wavelength Blue/purple light has... - ANS-a high frequency and a short wavelength Radio waves frequency - ANS-10 ^4 - 10 ^8 Hz Microwaves frequency - ANS-10^10 Hz Infrared frequency - ANS-10^13 Hz Visible light frequency - ANS-10^15 Hz Ultraviolet frequency - ANS-10^16 Hz X-rays frequency - ANS-10^18 Hz Gamma rays' frequency - ANS-10^20 Hz Radio waves - ANS-- Electromagnetic waves with the longest wavelengths and lowest frequencies - Emitted by radio and TV transmitters - Used to send radio and TV programmes - Detected by aerials and radios/TVs Microwaves - ANS-- Emitted by radio transmitters, mobile phones and microwave cookers - Used to carry information and to cook food - Can damage living tissue by heating it - Detected by aerials and radios/mobile phones Infrared radiation - ANS-- Emitted by warm and hot objects, and by TV remote or car locks - Detected by skin and thermometers - Too much infrared can burn the skin Visible light - ANS-Electromagnetic radiation that can be seen with the unaided eye and photographic film Ultraviolet waves - ANS-- Emitted from very hot objects including the Sun - Causes human skin to tan but can also cause skin cancer - Detected by photographic film X-rays - ANS-- Go through flesh but not bone - Used to look at bones inside the body - Can cause cancer Gamma rays - ANS-- Emitted from radioactive substances - Used to sterilise medical instruments - Can penetrate deep inside the body - Can cause cancer Recall the steps for the transmission of radio waves - ANS-1) Sound waves are detected by the microphone and converted into analogue radio waves 2) Radio waves are transmitted and detected by aerials 3) The radio waves vary in the same way the sound waves did 4) The receiver converts the radio waves back to the sound waves again Radio waves of relatively ___ frequencies can travel along the surface of the ______ retaining a good ______ reception for hundreds of ____. This type of radio is mainly used for _____ and national transmittance. - ANS-low, Earth, signal, miles, local Why are microwaves not reflected by the ionosphere? - ANSThey are of higher frequencies and energy Microwaves pass through the _________ and travel into _____ - ANS-ionosphere, space