What is the electromagnetic spectrum (long wavelength to short wavelength?
Red Monkeys In Vacuums Use X-ray Glasses (Radio waves, microwaves, Infrared, Visible light, Ultraviolet, X-ray, Gamma)
1 of 8
Which electromagnetic waves are dangerous to human body tissue?
-Ultraviolet (can cause skin to age prematurely and increase the risk of skin cancer, not ionising) -X-rays and Gamma rays are ionising and can cause mutations of genes and cancer
2 of 8
What are the uses of 1) Radio waves 2) Microwaves 3) Infrared 4) Visible light 5) Ultraviolet 6) X-rays and gamma rays
1) Television and radio 2)Satellite communications, cooking food 3)Electrical heaters, cooking food, infrared cameras 4)Fibre optic communications 5)Energy efficient lamps, sun tanning 6) medical imaging and treatments
3 of 8
Describe what happens when radio waves are absorbed by a receuver ariel
-Some of the wave is absorbed -This gives the electrons in the aerial energy making them move -The vibrations are sent through a wire to a circuit which decodes the wave into the relevant sounds etc
4 of 8
What properties do long wave radio waves (1-10km) have which make them good for transferring radio signals?
They can be received very long distances from where they are transmitted as they diffract (bend) around the earth including around hills and into tunnels. This means the signals can be received even if the receiver isn't visible from the transmitter
5 of 8
What properties do short wave radio waves (10-100m) have which make them good for transferring signals?
Like long-wave radio waves can be received at long distances from the transmitter. This is as they are reflected from the ionosphere- an electrically charged layer in the Earth's upper atmosphere. They're also used for short distance bluetooth
6 of 8
What are the properties of radio waves used for TV and FM radio transmissions?
These radio waves have very short wavelengths. To get reception you must be in direct sight of the transmitter as the signal doesn't bend or travel far through buildings
7 of 8
What properties do microwaves have which make them suitable for satellites?
-Microwaves can pass easily through the earth's atmosphere. For Satellite TV the signal is transmitted to space, picked up by a satellite dish and transmitted back to earth in a different direction where it's received by a satellite on the ground
8 of 8
Other cards in this set
Card 2
Front
Which electromagnetic waves are dangerous to human body tissue?
Back
-Ultraviolet (can cause skin to age prematurely and increase the risk of skin cancer, not ionising) -X-rays and Gamma rays are ionising and can cause mutations of genes and cancer
Card 3
Front
What are the uses of 1) Radio waves 2) Microwaves 3) Infrared 4) Visible light 5) Ultraviolet 6) X-rays and gamma rays
Back
Card 4
Front
Describe what happens when radio waves are absorbed by a receuver ariel
Back
Card 5
Front
What properties do long wave radio waves (1-10km) have which make them good for transferring radio signals?
Comments
No comments have yet been made