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Flashcards in deck_9958725 Deck (21)
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1
Q

<p>State the 7 electromagnetic waves found in the electromagnetic spectrum in order of increasing wavelength</p>

A

<p>Gamma, X Ray, UV, Visible, Infrared, Microwaves, Radio</p>

2
Q

<p>What is the highest frequency electromagnetic wave?</p>

A

<p>Gamma waves</p>

3
Q

<p>What is the highest energy electromagnetic wave?</p>

A

<p>Gamma wave</p>

4
Q

<p>What is the speed of EM waves in a vacuum?</p>

A

<p>3x108m/s</p>

5
Q

<p>A wave transmits energy from...</p>

A

<p>...source to absorber.<br></br>e.g. from a light source to the eye</p>

6
Q

<p>What range of frequencies of electromagnetic waves can be detected by the human eye?</p>

A

<p>400-700 nanometres</p>

7
Q

<p>What properties are shared by all electromagnetic waves?</p>

A

<ul> <li> <p>They are all transverse waves</p> </li> <li> <p>They all travel at the same speed (3 x 108m/s) in a vacuum</p> </li> <li> <p>They can travel through a vacuum</p> </li></ul>

8
Q

<p>State and explain a use of radio waves.</p>

A

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

9
Q

<p>State and explain a use of microwaves.</p>

A

<ul> <li>Microwaves are used for the purpose of satellite communications (transmitting signals between stations on Earth and satellites).</li> <li>Microwaves are also used to transmit signal from a nearby phone mast (transmitter) to a mobile phone.</li> <li>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.</li></ul>

10
Q

<p>State uses of infrared radiation.</p>

A

<ul> <li> <p>Infra-red radiation is used in TV controls</p> </li> <li> <p>Infra-red can also be used for security purposes such as in intruder alarms by detecting body heat.</p> </li></ul>

11
Q

<p>State and explain uses of infrared radiation.</p>

A

<p>Illuminating (i.e. seeing) and fibre optics, as they reflect best in glass (other waves have wavelengths that are too long/short).</p>

12
Q

<p>State and explain uses of UV radiation.</p>

A

<ul> <li> <p>Ultraviolet light is used in medical and forensic photography</p> </li> <li> <p>air purification</p> </li> <li> <p>disinfection and medical therapy</p> </li> <li> <p>Ultraviolet light can also be used to detect fake bank notes.</p> </li></ul>

13
Q

<p>State and explain uses of X rays.</p>

A

<ul> <li> <p>Low-energy X-rays are used for medical and industrial imaging.</p> </li> <li> <p>High-energy X-rays are used to treat cancer.</p> </li> <li> <p>X-rays are also used for security purposes to detect weapons in airports (and other places).</p> </li></ul>

14
Q

<p>State and explain uses of gamma rays.</p>

A

<ul> <li>Gamma rays are used in medical treatments, such as radiotherapy in the treatment of cancer.</li> <li>Astronomy</li> <li>Food preservation</li></ul>

15
Q

<p>How does UV radiation affect body tissue?</p>

A

<ul> <li> <p>UV radiation can cause cancer when skin is exposed to it.</p> </li> <li> <p>It can cause blindness if eyes are overexposed to UV radiation.</p> </li></ul>

16
Q

<p>How do X-rays affect body tissue?</p>

A

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

17
Q

<p>How do gamma rays affect body tissue?</p>

A

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

18
Q

<p>What are the safety precautions taken while using X-Rays?</p>

A

<ul> <li> <p>Due to the dangerous nature of X-rays, exposure to X-rays should always be kept to a minimum.</p> </li> <li> <p>People working with X-ray equipment should always shield themselves to prevent exposure to X-rays.</p> </li> <li> <p>These people will place materials (metals for example lead) between themselves and the X-rays.</p> </li></ul>

19
Q

<p>What are the risks of Infra-red radiation</p>

A

<ul> <li> <p>Infra-red radiation can cause serious skin burns if emitted from high-intensity sources.</p> </li></ul>

20
Q

<p>What are the risks of microwaves (the actual wave)?</p>

A

<ul> <li>Because humans are largely made up of water, exposure to microwaves could have a harmful effect.</li></ul>

21
Q

<p>What are risks of radio waves?</p>

A

<ul> <li>At high intensities, radio waves can cause internal heating of living tissue with potentially harmful effects.</li></ul>