P13 - Electromagnetic Waves Flashcards
1
Q
2 properties:
electromagnetic waves
A
- transverse
- 300,000,000 m/s in a vacuum
- (electrical and magnetic fields)
2
Q
list:
electromagnetic spectrum
(high to low wavelength)
A
- radio waves
- microwaves
- infrared
- visible light
- ultraviolet
- x-rays
- gamma rays
3
Q
How are radio waves produced?
A
Oscilliations in electrical circuits (AC)
Hz of AC is same as Hz of wave
4
Q
What happens when radio waves are absorbed?
A
Induce oscillations in an electrical
circuit (create AC)
with the same Hz as the wave
5
Q
How does ionising radiation cause harm?
A
They knock off electrons from their shells forming ions. These ions may be inside a cell which causes them to be more reactive. This can cause death of tissue cells, or if in the nucleus, mutations which cause cancerous growths.
6
Q
list:
uses of electromagnetic waves
A
- radio waves and microwaves – long distance communications
- infrared – heating
- visible light – fibre optic communications
- ultraviolet – tanning
- X-rays and gamma rays – medical imaging and treatments