Topic 3.3 - Electromagnetic Spectrum Flashcards Preview

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Flashcards in Topic 3.3 - Electromagnetic Spectrum Deck (21)
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State the 7 electromagnetic waves found in the electromagnetic spectrum in order of increasing wavelength

Gamma, X Ray, UV, Visible, Infrared, Microwaves, Radio


What is the highest frequency electromagnetic wave?

Gamma waves


What is the highest energy electromagnetic wave?

Gamma wave 


What is the speed of EM waves in a vacuum?



A wave transmits energy from...

...source to absorber.
e.g. from a light source to the eye


What range of frequencies of electromagnetic waves can be detected by the human eye?

400-700 nanometres


What properties are shared by all electromagnetic waves?

  • They are all transverse waves

  • They all travel at the same speed (3 x 108m/s) in a vacuum

  • They can travel through a vacuum


State and explain a use of radio waves.

Communications, because radio waves are long wavelength and can travel long distances without losing quality.


State and explain a use of microwaves.

  • Microwaves are used for the purpose of satellite communications (transmitting signals between stations on Earth and satellites).
  • Microwaves are also used to transmit signal from a nearby phone mast (transmitter) to a mobile phone.
  • Microwaves are absorbed by water, heating up the water in the process. This makes microwaves useful for cooking food because food contains lots of water.


State uses of infrared radiation.

  • Infra-red radiation is used in TV controls

  • Infra-red can also be used for security purposes such as in intruder alarms by detecting body heat.


State and explain uses of UV radiation.

  • Ultraviolet light is used in medical and forensic photography

  • air purification

  • disinfection and medical therapy

  • Ultraviolet light can also be used to detect fake bank notes.


State and explain uses of X rays.

  • Low-energy X-rays are used for medical and industrial imaging.

  • High-energy X-rays are used to treat cancer.

  • X-rays are also used for security purposes to detect weapons in airports (and other places).


State and explain uses of gamma rays.

  • Gamma rays are used in medical treatments, such as radiotherapy in the treatment of cancer.
  • Astronomy 
  • Food preservation


How does UV radiation affect body tissue?

  • UV radiation can cause cancer when skin is exposed to it.

  • It can cause blindness if eyes are overexposed to UV radiation.


How do X-rays affect body tissue?

X-rays are ionising so they can damage or kill cells and cause mutations that could lead to cancer.


How do gamma rays affect body tissue?

Gamma rays are even more ionising than X-rays, so they can cause cell mutations (which can lead to cancer) and cell death.


What are the safety precautions taken while using X-Rays?

  • Due to the dangerous nature of X-rays, exposure to X-rays should always be kept to a minimum.

  • People working with X-ray equipment should always shield themselves to prevent exposure to X-rays.

  • These people will place materials (metals for example lead) between themselves and the X-rays.


What are the risks of Infra-red radiation 

  • Infra-red radiation can cause serious skin burns if emitted from high-intensity sources.


What are the risks of microwaves (the actual wave)?

  • Because humans are largely made up of water, exposure to microwaves could have a harmful effect.


What are risks of radio waves?

  • At high intensities, radio waves can cause internal heating of living tissue with potentially harmful effects.