Physics
Physics E.M. Sprectrum
Increasing Wavelength
g
X-Rays
Ultra-Violet Rays
Violet
Indigo
Blue
Green
Yellow
Orange
Red
Radio Waves
Properties
They can be reflected or refracted.
They all obey the wave equation
Velocity= Frequency x Wavelength
They transfer energy from one place to another.
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 are transverse Waves.
They can travel through Vacuum.
2 Kinds of Radiation emitted from electromagnetic rays
Ionising radiation
Are harmful and can damage living cells and tissues
Non-ionising radiation
Non harmful radiation which would not harm living cells and tissues
Increasing Frequency
Radio waves
Radio and television communication
Microwaves
Radar communication , Microwave cooking
Infra-red
Intruder alarms, Remote control of electrical appliances , Radiant heater
Visible Light
Photosynthesis, Lasers for medical , industrial and surveying
Ultra-violet Rays
Sunbeds , Forgery detection
X-rays
Airport Security, Medical/Dental inspections, Analysis of crystal structure
Gamma Rays
Treatment of cancer, Sterilising equipment
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.
