Sources & Uses of Electromagnetic Waves (SQA National 5 Physics): Revision Note

Sources & uses of electromagnetic waves

Radio waves

• Sources

  • Wires carrying alternating current

  • Objects in the universe (e.g. pulsars)

• Detectors

  • Aerials/antenna

  • Radio telescopes

• Uses

  • Radio and television transmissions

  • Pager communication

  • Radio frequency identification

Microwaves

• Sources

  • Cosmic microwave background radiation (CMBR)

  • Magnetron

• Detectors

  • Aerials/antenna

• Uses

  • Satellite television

  • Mobile (cell) phones

  • Microwave ovens

  • GPS (Global Positioning Systems)

  • Wireless headphones

Infrared

• Sources

  • Any warm object

• Detectors

  • Infrared camera

  • Thermograms

  • Thermistor

• Uses

  • Electric grills

  • Television remote controllers

  • Intruder alarms

  • Thermal imaging

  • Optical fibres

Visible light

• Sources

  • Stars (e.g. the Sun)

  • LEDs

  • Hot filaments of lamps

• Detectors

  • Eyes

  • CCDs in cameras

  • Light-dependent resistor (LDR)

• Uses

  • Vision

  • Photography

  • Illumination

Ultraviolet

• Sources

  • Stars (e.g. the Sun)

  • UV tubes

• Detectors

  • Fluorescent materials

• Uses

  • Producing vitamin D

  • Checking security markings on banknotes

  • Disinfecting hospital instruments

  • Treating skin conditions & jaundice

  • Setting composite materials (e.g. nail gel, dental fillings)

  • Tanning sunbeds

X-rays

• Sources

  • X-ray tubes

  • Particle accelerators

• Detectors

  • Photographic film

• Uses

  • Medical scanning

  • Dental scanning

  • Airport security scanners

Gamma rays

• Sources

  • Radioactive substances

  • Objects in the universe (e.g. gamma ray bursts)

• Detectors

  • Geiger-Muller (GM) tube

  • Photographic film

• Uses

  • Sterilising food

  • Sterilising medical equipment

  • Detection of cancer

  • Treatment of cancer