Flashcards
the electromagnetic spectrum
Cards in this deck (13)
- 1what kind of waves are electromagnetic onestransverse waves
- 2what does the electromagnetic spectrum extend fromfrom low frequency, low energy waves to high frequency, high energy waves. Human eyes are only capable of detecting visible light i.e a very limited range of electromagnetic waves
- 3what does the wavelength of an electromagnetic wave effecthow it is absorbed, transmitted,reflected or refracted by different substances. This affects its uses
- 4what are the 7 electromagnetic waves-radio waves
-microwaves
-infrared waves
-visible light
-ultraviolet waves
-x-rays
-gamma rays - 5what are all the EM waves usesradio waves-television, radio, Bluetooth
microwaves-satellite communications, cooking food
infrared waves-electrical heaters,cooking food, infrared cameras
visible light-fibre optic communications
ultraviolet waves-energy efficient light bulbs, security marking, sunbeds
x-rays- medical imaging and treatments
gamma rays-sterilising food, treatment of tumours - 6why are these EM waves used for these things( explanations)-first 4radio waves-they are low energy therefore they are not harmful making them ideal for radio transmission
microwaves-travel in straight lines through the atmosphere, this makes them ideal fr transmitting signals to satellites in orbit and transmitting them back o the receivers
infrared waves -glow red hot as electricity flows through them, this transmits infrared energy that is absorbed by the food and converted back into heat
visible light-it travels down optical fibres from one end to the other without being lost through the sides - 7why are these EM waves used for these things( explanations)-last 3ultra-violet waves-in energy efficient light bulbs, UV waves are produced by the gas in the bulb when it is excited by the electric current ...these UV waves are absorbed by the coating on the bulb which fluoresces giving off visible light
x-rays- able to penetrate soft tissue but not bone...a photographic plate behind a person will show shadows where bones are
gamma rays-these are the most energetic of all electromagnetic waves and can be used to destroy bacteria and tumours - 8RP) write a method to investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of the surface1)take four boiling tubes each painted a different colour:matt black, gloss black, white and silvered
2- pour hot water into each boiling tube
3-measure and record the start temperature of each tube
4-measure the temperature of each tube every minute for 10 minutes
5-the tube that cools the fastest emits infrared energy quickest - 9what can radio waves be caused byoscillations in the electrical circuits, i.e an altering current.
- 10how is a radio signal producedThe frequency of the radio wave produced matches the frequency of the electrical oscillation. This is how a radio signal is produced
- 11how is the signal recievedwhen radio waves are absorbed by a conductor they may create an alternating current with the same frequency as the radio wave
- 12what can changes in atoms and the nuclei of atoms result init can result in EM waves being generated or absorbed over a wide frequency range:
-electrons moving between energy levels as a result of heat or electrical excitation can generate waves e.g infrared waves, visible light, ultra-violet waves and x-rays
-changes in the nucleus of an atom can generate waves i.e an unstable nucleus can give out excess energy as gamma rays - 13which EM waves are hazards to the human body and why-ultraviolet waves can cause the skin to age prematurely and increase the risk of skin cancer
-x-rays and gamma rays are ionising radiation- they can damage cells by ionising atoms and if absorbed by the nucleus of the cell ,can cause gene mutations and cancer
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- GCSE physics new Flashcards on the electromagnetic spectrum, created by ella stokes on 05/11/2017.
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- ella stokes
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