The Electromagnetic Spectrum Flashcards
Define electromagnetic waves
Transfer energy from one place to another
Don’t need matter to move - can move through vacuum
All travel at the same speed (3x10 8 m/s) in a vacuum as well as air
Describe the order of the electromagnetic system, starting with the waves with the lowest frequency.
Radio
Microwaves
Infrared
Visible Light
Ultraviolet
X-ray
Gamma
What are the 3 things that happen when moving along the electromagnetic spectrum from radio to gamma?
Frequency increases
Wave energy increases
Wavelength gets smaller
Describe radio wave’s uses and dangers.
USES:
Radio and TV transmission
Astronomy
Radio frequency identification
DANGERS:
None
Describe microwave’s uses and dangers.
USES:
Satellite TV
Mobile phones
Microwave ovens
DANGERS:
Internal heating of body cells
Describe infrared’s uses and dangers.
USES:
Electric grills
Short range comms
Remote controllers
Intruder alarms
Thermal imaging
Optical fibres
DANGERS:
Skin burns
Describe visible light’s uses and dangers.
USES:
Vision
Photography
Illumination
DANGERS:
None
Describe ultraviolet’s uses and dangers.
USES:
Security marking
Detecting fake book notes
Sterilising water
DANGERS:
Damage to surface cells and eyes, leading to skin cancer and eye conditions
Describe X-ray’s uses and dangers.
USES:
Medical scanning
Security scanners
DANGERS:
Mutation or damage to the cells in the body
Describe gamma’s uses and dangers.
USES:
Sterilising food and medical equipment
Detection of cancer and its treatment
DANGERS:
Mutation or damage to the cells in the body
Describe analogue vs digital signals.
Analogue signals can vary continuously in frequency, amplitude or both. Digital signals are a series of pulses consisting of just 2 states, on and off. No values inbetween.
Describe the advantages of digital signals.
Carry more info per second than analogue signals
Maintain their quality over long distances better than analogue signals
