1. What are EM Waves ? EM waves are non mechanical and transverse waves which consists of Magnetic and Electric Fields oscillating perpendicularly to each other
2. Properties and Dangers
2.1. Gamma Rays have the highest frequency of the EM spectrum and are the most penetrative. It can kill cancer cells but also healthy tissues resulting in Nausea, Hair loss
2.2. X-Rays have high frequencies and high penetrative abilities. Exposure to X-Rays is considered hazardous, posing cancer risk from radiation
2.3. UV Rays stimulates production of Melanin in our skin pigments. Excessive Exposure can cause Sunburn and Skin Cancer from DNA damage
2.4. Visible Light consists of an infinite possibility of colours, mainly the ones we can perceive are Red,Orange,Yellow,Green,Blue,Indigo,Violet.
2.5. Infrared Radiation is emitted by all objects.Higher temperature results in a higher frequency of the wave.
2.6. Microwaves are radio waves with short wavelengths. Microwaves subjected to oscillating electromagnetic fields result in highly polar water molecules rotating rapidly. Heat is generated from the friction among water molecules.
2.7. Radio Waves have the lowest frequencies and the longest wavelengths. Lowest frequency radio waves are reflected on an electrically charged layer called the lonosphere.
3. Properties of EM Waves
3.1. Transverse Waves
3.2. Constant Speed 3.0x10^8
3.3. Does not require a Medium
3.4. Obey Laws of Reflection & Refraction
3.5. Speed of light = Frequency ( Wave Length )
3.6. When travelling from one medium to another, Speed and Wavelength change but Frequency does not
4. Electro Magnetic Spectrum
4.1. Gamma Rays
4.1.1. Emitted during Radioactive decay of unstable atoms and Nuclear Reactions
4.1.1.1. Helps to kill cancerous tumours and cells. And also to kill harmful bacteria and viruses
4.2. X-Rays
4.2.1. Found from X-Ray tubes
4.2.1.1. Used in X-Ray tests to detect damages to bone. Also used as scanners at Airports
4.3. Ultraviolet Rays
4.3.1. Found in Mercury Vapour Lamps, Sun
4.3.1.1. Used to detect forgery
4.3.1.1.1. Can cause Sunburn , Skin Cancer
4.4. Visible Light
4.4.1. Emitted from Sun, Heated Bodies
4.4.1.1. Used in Optical Fibres, Light Photography and Endoscopy
4.5. Infrared
4.5.1. Emitted from Sun
4.5.1.1. Used in Remote Control of Household devices. eg TV , Radio. Also in Night Vision Equipment and Thermal Imaging Cameras.
4.6. MicroWaves
4.6.1. Found in Klystron Tube
4.6.1.1. Used for MicroWave Ovens, Satellites Transmission Systems and Mobile Phone Communications
4.7. Radio Waves
4.7.1. Found in Radio Transmission Device
4.7.1.1. Used in Radios, Remote Control Cars