Zusammenfassung der Ressource
Electromagnetic waves
- Properties
- All possess both a magnetic
wave and an electrical wave
interlocked and at right angles
to each other
- All can travel through a vacuum
- All transverse waves
- In free space travel at approx. 300,000,000 m/s
- Types
- Radio waves
- Wavelength - 10^-1 - 10^4
- Frequency - 3x10^9 - 3x10^4
- Made by electrons
oscillated by electric
fields in aerials
- Detected by resonance in
electric circuits
- Used for
telecommunications
- Microwaves
- Wavelength - 10^-4 - 10^-1
- Frequency - 3x10^12 - 3x10^9
- Produced by magnetron, klystron
oscillators, using electrons to set up
oscillations in a cavity
- Detected by heating effect
and electronic circuits
- Used for mobile phones,
radar, microwave ovens
- Infrared
- Wavelength -
7.4x10^-7 - 10^-3
- Frequency -
4x10^14 - 3x10^11
- Produced by the oscillation of
molecules from all objects at
any temp above absolute 0
- Detected by heating of
skin, photographic film
- Used for heaters, night vision
equipment, remote controls
- Visible light
- Wavelength - 3.7x10^-7 -
7.4x10^-7
- Frequency - 8x10^14 - 4x10^14
- Produced from high-temp
solids and gases, lasers
- Detected by photographic
film, retina of eye
- Used for sight, communication
- Ultraviolet
- Wavelength - 10^-9 - 3.7x10^-7
- Frequency - 3x10^17 - 8x10^14
- Produced by high-temp solids and gases
- Detected by photographic film, phosphors and sunburn
- Used for disco lights,
- X-Rays
- Wavelength - 10^-12 - 10^-7
- Frequency - 3x10^20 - 3x10^15
- Produced by bombarding
metals with high energy
electrons
- Detected by photographic film or fluorescence
- Used for medical analysis
- Gamma
- Wavelength - 10^-16 - 10^-9
- Frequency - 3x10^17 - 3x10^24
- Produced by nuclear decay or
by a nuclear accelerator
- Detected by a Geiger
counter or photographic
film
- Used for radiotherapy -
cancer treatment