4. Electromagnetic Waves Flashcards
Electromagnetic Waves
6 Properties
All electromagnetic waves:
- are made up of electric and magnetic fields oscillating perpendicularly to the direction of wave propagation
- are transverse waves
- do not carry electric charges
- can travel without a medium, with a speed of 3.0 x 108 m/s in a vacuum (no matter what type)
- undergo reflection and refraction
- transfer energy
v = fλ applies to all electromagnetic waves
State the order of electromagnetic waves based on increasing wavelength
- Gamma rays
- X-rays
- Ultraviolet radiation
- Visible Light
- Infrared radiation
- Microwaves
- Radio waves
State the order of electromagnetic waves based on increasing frequency
- Radio waves
- Microwaves
- Infrared Radiation
- Visible Light
- Ultraviolet radiation
- X-rays
- Gamma rays
Radio Waves
Examples
- Television and radio communication
- Radio telescopes for radio astronomy
Microwaves
Examples and Hazardous Effects
Examples:
1. Microwave oven
2. Wi-fi signals
3. Mobile Phone communication
4. Global Positioning System
Hazardous effects:
Heating effect (temperature increases)
Infared Radiation
Examples and Hazardous Effects
Examples:
1. Remote control
2. Intruder alarm
3. Thermal imaging (infared camera)
Hazardous effect:
Heating effect (temperature increases)
Visible Light
Examples
- Photography
- Optical fibres in medicine and telecommunication
Ultraviolet Radiation
Examples and Hazardous Effects
Examples:
1. Sterilisation of medical equipment
2. Sunbed for artificial tanning
Hazardous effects:
1. Prolonged exposure to UV radiation can lead to sunburns, premature aging and increased risk of skin cancer
2. UV radiation can be ionising
Ionising Radiation
What is it and Effects
- Radiation that has the energy to remove elections from atoms or molecules, thereby ionising them.
- Exposure to ionising radiation can lead to cell death, mutations and abnormal cell division.
- May cause cancers such as leukaemia or deformities to a developing foetus
X-rays
Examples and Hazardous Effects
Examples:
- Scan luggage for prohibited items at airport
- Radiograpy to produce X-ray imaging to diagnose fractured bones or tooth decay
Hazardous Effects:
- Ionising radiation
Gamma Rays
Examples and Hazardous Effects
Examples:
1. Sterilisation of medical equipment
2. Sterilisation of food
Hazardous Effects:
1. Ionsing radiaton