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The EM spectrum - Coggle Diagram
The EM spectrum
Basics
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Transfer energy to the observe, infrared radiation transfers energy from the sun to the earth
Radio Waves
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When radio waves reach a receiver, the waves are absorbed and the enegry transferred.
This causes the electrons in the receives to oscillate, producing a current the same frequency as the radio waves that generated it
Uses
Long Wave - Can be transmitted and received halfway round the world. Used in internaitonal TV/ Radio
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TV signals and FM radio - Very short wavelength, to get reception you muct be in direct sight of the transmitter
Infrared radiaiton
IR cameras
IR radiation is given out by all objects, the hotter the object, the more radiation it gives out
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Electric heaters
Energy is transferred by IR waves to the thermal energy stores, causing their temperature to increase
Dangers of EM waves
Can harm people
High frequency waves like UV, X-Rays and gamma rays all transfer lots of energy and can cause alot of damage
UV radiation damages surface cells, which can cause skin to age prematurely, and cause skin cancer
X-rays and gamma rays are types of ionising radiation, they can cause gene mutation and cancer
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Microwaves
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Cooking
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Microwaves can heat water, so they can heat water inside our bodies, which can damage them
Ultraviolet radiaiton
Sun tans
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Exposure to UV radiaiton can be dangerous, can cause sunburn, which can lead to skin cancer
Security ink
When UV radiaiton hits certain chemicals, its absorbed and visible ligth is emitted
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X rays and gamma rays
Medical imaging
Dense materials like bone absorbs radiaiton, this can be measured and it gives you an X-Ray image, can cause mutations to DNA, which can cause cancer
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