Electromagnetic Waves

Electromagnetic Waves
It was once the great Scottish physicist James Clerk Maxwell (1831-1879) who had presented that electric and magnetic fields unstable together can form a spreading wave, appropriately called an electromagnetic wave. The properties of an electromagnetic wave are as follows:
1. They can travel through a vacuum at the same high speed, which is much faster than other types of waves that travel through a material.
2. They show the normal wave properties of reflection, refraction and diffraction.
3. They are transverse waves.
4. They travel due to moving electric and magnetic fields.
The Sun and other stars give off a wide range of types of electromagnetic waves, which travel through space to Earth. Much of this radiation is stopped by Earth’s atmosphere and can only be detected by satellites in orbit outside the atmosphere.
Electromagnetic Waves consist of oscillating electric and magnetic fields which can travel through a vacuum while all other type of waves need a medium to travel.
The types of electromagnetic waves in order of increasing wavelength are described below:
1. Gamma Rays are produced by radioactive substances. They are very dangerous to living matter. They are used to kill cancer cells and dangerous bacteria.
2. X-Rays are produced in high voltage X-ray tubes. They can also be dangerous to living matter. They are absorbed differently by different types of matter so can produce shadow pictures if inside the human body or inaccessible metal structures.
3. Ultraviolet (UV) Radiation is produced by the Sub, special UV tubes and welding arcs. The radiation can cause sunburn and skin cancer; it also produces vitamins in the skin and causes certain substances to fluoresce. This fluorescence can reveal markings that are invisible in light. Special photographic films react to UV radiation.
4. Visible Light is a very narrow range of wavelengths that can be seen by the human eye as the colours of the visible spectrum from violet to red. Normal photographic films are designed to be sensitive to visible light.
5. Infrared (IR) Radiation is produced by hot objects and transfers heat to cooler objects. Hot objects below about 500 Degrees Celsius produce only IR radiation; above this temperature, visible lights is also radiated. Special photographic films react to IR radiation given off by warm objects.
6. Radio Waves came in a wide range of wavelengths that can be split into these groups:
Microwaves have very short wavelengths, close to that of IR radiation. They are used for telecommunication, both ground based and via satellites. They are also used for radar and cooking.
VHF (very high frequency) and UHF (ultra high frequency), of longer wavelengths, are used for television and radio.
Traditional radio waves (short, medium and long wave) have the longest wavelengths.

The fundamental difference between electromagnetic waves and other types of waves is that electromagnetic waves can transfer energy without transferring mass.

Bibliography
1. "Uses of Electromagnetic Waves." Revision World. N.P., n.d. Web. 13 Apr. 2014. .
2. "Electromagnetic Spectrum." GCSE Physics Uses of Waves Revision -. N.P., n.d. Web. 13 Apr. 2014. .
3. "Electromagnetic Waves." Electromagnetic Waves. N.P., n.d. Web. 13 Apr. 2014. .
4. "Electromagnetic Waves." The Physics Hypertextbook. Glenn Elert, n.d. Web. 13 Apr. 2014. .
5. Palma, Dr. Christopher. "Radio Waves to Gamma-rays." Welcome! The Pennsylvania State University, n.d. Web. 13 Apr. 2014. .
6. "Electromagnetic Radiation." Wikipedia. Wikimedia Foundation, n.d. Web. 13 Apr. 2014. .
7. Ronca, Debra. "How Radiation Works." HowStuffWorks. HowStuffWorks.com, 23 July 2008. Web. 13 Apr. 2014. .
8. http://www.phy.ilstu.edu/~ren/phy102ren/Ch06-sfr-09.pdf
9. PDF Files (Attached in Mail)
10. Complete Physics for Cambridge IGCSE Second Edition by Stephen Pople

Bibliography: 1. "Uses of Electromagnetic Waves." Revision World. N.P., n.d. Web. 13 Apr. 2014. . 2. "Electromagnetic Spectrum." GCSE Physics Uses of Waves Revision -. N.P., n.d. Web. 13 Apr. 2014. . 3. "Electromagnetic Waves." Electromagnetic Waves. N.P., n.d. Web. 13 Apr. 2014. . 4. "Electromagnetic Waves." The Physics Hypertextbook. Glenn Elert, n.d. Web. 13 Apr. 2014. . 5. Palma, Dr. Christopher. "Radio Waves to Gamma-rays." Welcome! The Pennsylvania State University, n.d. Web. 13 Apr. 2014. . 6. "Electromagnetic Radiation." Wikipedia. Wikimedia Foundation, n.d. Web. 13 Apr. 2014. . 7. Ronca, Debra. "How Radiation Works." HowStuffWorks. HowStuffWorks.com, 23 July 2008. Web. 13 Apr. 2014. . 8. http://www.phy.ilstu.edu/~ren/phy102ren/Ch06-sfr-09.pdf 9. PDF Files (Attached in Mail) 10. Complete Physics for Cambridge IGCSE Second Edition by Stephen Pople