The Electromagnetic Spectrum Flashcards
Electromagnetic waves are________ waves and travel at the______ _______ through a vacuum
- transverse
2. Same speed
The electromagnetic spectrum
Radio, microwave, Infra-red, visible light, ultra violet , X Ray, gamma ray
What are electromagnetic waves?
Electromagnetic waves are electric and magnet disturbances that transfer energy from one place to another.
Infra-red
Infra-red is used for carrying signals from remote handsets and in optical fibres. It is also used in infra red camera and infra red scanners in hospitals
Microwave
Microwaves carry mobile phone calls. Further research is needed to evaluate whether or not mobile phones are safe
________ ________ of electromagnetic radiation have________ ____ ___ _____.
Different wavelength
Different effects on living cells
Microwaves
Microwaves can cause internal hearing, they are called microwaves because they have shorter wavelengths than radio.
What are microwaves used for?
They are used for satellite tv because they can pass through the atmosphere and reach satellites above the earth. They are also used to carry mobile phone signals.
Radio waves
They have frequencies ranging from 300,000 to 3000 million hertz.
How are radio waves produced?
They can be produced by oscillations in electrical circuits.
What are radio waves used for?
Bluetooth enabled devices can communicate without being connected by wires. A Bluetooth radio is fitted to each device.
What are infrared used for?
They are used for communications, infrared radiation is also used in remote control handsets and infrared cameras.
Ultraviolet
Contain chemicals to absorb UV and emit light.
How does an ultraviolet lamp work?
The ink in security marker pens is invisible until you shine a UV lamp on it.
What are the disadvantages of using UV?
They can cause skin to age prematurely and increase the risk of skin cancer.
X rays
X rays pass through soft tissue but are absorbed by bone.
What are X rays used for?
They are used in hospitals to take radiographs (X Ray images)
Why are X rays and gamma rays bad?
X rays are a type of ionising radiation which can cause the mutation of genes. This can lead to cancer.
Gamma rays
Gamma rays originate from changes in the nucleus of an atom.
What are gamma rays used for?
Gamma rays are used in hospital to kill cancer cells. They are also used to kill harmful bacteria and sterilise medical equipment.
Electromagnetic waves are________ waves and travel at the_____ _____ through a vacuum(300 million m/s)
- Transverse
2. same speed
