Physics E.M. Sprectrum
Effects of E.M. Waves
Infrared heating
Our skin absorbs the infrared waves which makes us feel warm. The source of this heat can be seen like the red colour of a hot charcoal.
Increasing Frequency
Gamma Rays
Treatment of cancer, Sterilising equipment
X-rays
Airport Security, Medical/Dental inspections, Analysis of crystal structure
Ultra-violet Rays
Sunbeds , Forgery detection
Visible Light
Photosynthesis, Lasers for medical , industrial and surveying
Infra-red
Intruder alarms, Remote control of electrical appliances , Radiant heater
Microwaves
Radar communication , Microwave cooking
Radio waves
Radio and television communication
2 Kinds of Radiation emitted from electromagnetic rays
Non-ionising radiation
Non harmful radiation which would not harm living cells and tissues
Ionising radiation
Are harmful and can damage living cells and tissues
Properties
They can travel through Vacuum.
They are transverse Waves.
All travel at the speed of light (3x10^8 ms^-1 in air and a vacuum. They will slow down when travelling through water or glass.
They transfer energy from one place to another.
They all obey the wave equation
Velocity= Frequency x Wavelength
They can be reflected or refracted.
Increasing Wavelength
Radio Waves
Microwaves
Infra-red
Visible Light
Red
Orange
Yellow
Green
Blue
Indigo
Violet
Ultra-Violet Rays
X-Rays
Gamma Rays