Electromagnitic Waves Flashcards
All electromagnetic waves travel at the same _________
Speed
What are electromagnetic radiations
Electric and magnetic disturbances
Electromagnetic waves have different _______ and ________
Wavelengths
Frequencies
Which electromagnetic wave has the shortest wavelength but the highest frequency
Gamma
Which waves have the longest wavelength but the lowest frequency
Radio waves
In terms of energy, what does a higher frequency of a wave mean
The more energy it transfers
What are microwaves used for
Communications
Why are microwaves used to transmit signals to satellites
Microwave transmitters produce wavelengths that are able to pass though the earths atmosphere
What are radio waves used to transmit
Radio, TV, programmes and mobile phone signals
Why are microwaves and radio waves bad for your health
They penetrate your skin and are absorbed by body tissue, this can heat internal organs and may damage them
Why is infrared radiation bad for your health
It is absorbed by the skin and causes burns to the skin
Why is the radio and microwave spectrum split up into bands
Different bands are used for different communication purposes
How are radio waves produced
By applying an alternating voltage to an
The shorter the wavelength of an electromagnetic wave, _____ information they carry
More
What are optical fibres
They are very thin glass fibres
