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Electronmagnetic Waves

Effects of Electronmagnetic Waves

Ionisation and effects of ionising radiation on living matter

Ionising radiation is encountered in cosmic rays which originate form space and the Sun. They also can be produced artificially using X-rays.

The damage it does to the body: 1)Damage to proteins, nucleic acids and other vital molecules found in cells. 2)Damage to chromosomes. 3)A pregnant woman risks giving birth to a deformed baby. 4)Risks of getting cancers like leukaemia. 5)Premature aging and shortening of lifespan.

High energy electromagnetic waves like UV rays and X-rays are able to ionise atoms and molecules.

Infared Heating

Our skins absorb the infrared waves which make us feel warm. The source of this heat can be seen like the red colour of a hot charcoal.

Applications of Electronmagnetic Waves

Radio waves

able to go around without any obstructions due to their longer wavelengths

used in radio broadcasting, wireless telegraphy, telecommunications etc.

Microwaves

Satellite television use microwaves to receive TV programmes

unable to go around without any obstructions due to their shorter wavelengths

causes water molecules in food to vibrate at millions times per second and creates friction to heat up the food

can penetrate haze, light, rain, snow, clouds and smoke

Infrared

Amount of infrared energy emitted by a human body depends on its temperature

infrared remote controllers used to control many electrical devices like TV

Visible light

used in opitical fibres for telecommunications

light is used in opitical fibres for medicial purposes

Ultraviolet

divided into three bands:

UVB and UVC rays

used as germicidal lamps for sterilisation in hospitals

UVA rays

UV lamps emit UVA are used in sunbeds for artificial tanning

UV rays are part of the sunlight that causes sunburn and tans

X-rays

can also be used in daily applications like X-rays scanner at airports

used to produce X-ray images for doctors to diagnose the fracture of a broken arm etc.

can also be used for radiation therapy

Gamma rays

y-rays used to destroy brain tumor

uses to treat cancer

high energy rays

Properties of Electronmagnetic Waves

Their frequencies does not change when they travel form one medium to another. Only their speeds and wavelength will change.

They have no electric charge.

They obey the laws of reflection and refraction.

The formulae is v=fl

They travel at the speed of 3x108 m/s in vaccuum. They will slow down when travelling through water or glass.

Do not require any medium to travel from point to point.

Electromagnetic waves transfer energy from one place to another.

All electromagnetic waves are transverse

What is Electronmagnetic Waves?

Electronic waves belongs to the electromagnetic spectrum. It consists of radio waves, microwaves, infrared, visible light,ultraviolet,x-ray and gamma ray.