Presentation on theme: "By Will B. Electromagnetic waves The different waves that make up the electromagnetic spectrum are as follows in order of increasing frequency; Radio."— Presentation transcript:
Electromagnetic waves The different waves that make up the electromagnetic spectrum are as follows in order of increasing frequency; Radio -> Microwave -> Infrared -> Light -> Ultraviolet -> X-ray -> Gamma. All these waves can travel through a vacuum. They are also all transverse waves.
Radio Waves Has a frequency of 10 3 – 10 12 Hertz Has a wavelength of 10 5 – 10 -4 Radio waves will be reflected and refracted by the ionosphere as it is electrically charged. Radio waves main uses are radio and television broadcasts. Radio waves can produce a chosen frequency, so they won’t interfere with other radio waves. This allows for more than one radio station to broadcast in an area.
Have a frequency of 10 3 to 10 12 hertz Have a wavelength of 10 5 to 10 -4 metres Microwaves are not reflected by the ionosphere and so are used for communications with satellites. Microwaves have shorter wavelengths, this makes them ideal for handheld communication devices such as mobile phones.
Has a frequency of 10 11 to 10 13 hertz Has a wavelength of 10 -3 to 10 -5 They use total internal reflection to be carried along optical fibres. They are responsible for heat radiation, when you feel warmth from a bonfire, it is because infrared waves carry the heat. Infrared waves are also used in toasters and grills to cook food.
Human eyes can detect electromagnetic wavelengths from about 400nm (violet) to 700nm (red). Visible light can be totally internally reflected within glass. This allows images to be transported directly from one place to another.
Has a frequency ranging from 7.5 x 1014 to 3 x 1016 hertz. Has a wavelength 10-6 to 10-9 Some ultraviolet waves are used in the treatment of sewage to kill bacteria. To much exposure to ultraviolet waves can cause sunburn in humans.
Has a frequency of 10 15 to 10 20 Has a wavelength of 10 -7 to 10 -12 Very high energy electromagnetic waves can be produced by colliding high speed electrons with a metal target. When these electrons decelerate rapidly, they give off energy as x-rays.
Has a frequency of 1017 to 1024 Has a wavelength of 10-9 to 10-16 Generated by energy shifts inside the nuclei of atoms, gamma rays form the very highest energy EM waves. Used to sterilise surgical instruments Gamma rays can be used to kill cancerous cells in the body.