WAVES

• Wave - a disturbance in space
• crest - the highest point in a wave
• trough - the lowest point of a wave
• amplitude - it is the distance midpoint to the highest (or lowest) point of a wave
• wavelength - it is the distance between 2 successive identical parts of a wave
• frequency - refers to the amount of waves produced in one second.
• range - refers to the extent or limits between which variation is possible
• Electromagnetic wave theory states that the oscillating electric current should be capable of radiating energy in the form of electromagnetic waves.
• Heinrich Hertz discovered the 'hertzian waves' which is now known today as radio waves.
• what is the unit used in measuring the frequency of waves? Hertz (Hz)
• EM waves can travel through a vacuum
• EM waves are disturbances in a field rather than a medium
• EM waves form when moving charge particles transfer energy through a field.
• Electromagnetic wave or electric radiation - a wave that is created as a result of vibrations between an electric field and magnetic field
• Oersted`s discovery a changing electric field produces magnetic field.
• Michael Faraday`s discovery the changing magnetic field will produce electric field
• Electromagnetic Spectrum - the arrangement of electromagnetic waves in a gradual progression from the waves of lowest frequency to the waves of highest frequency.
• In order of increasing frequency the EM includes #1 radio waves, #2 microwave, #3 infrared, #4 visible lights, #5 ultra violet, #6 X-ray , #7 gamma ray
• radio waves - radio/television signals, global positioning system, and magnetic resonance imaging
• microwave - satellite communication, terrestrial communication, and cook
• infrared - remote control, thermal imaging through infrared scanner, and night vision goggles
• visible lights - artificial light and optical fibers
• ultra violet - security markings, sterilization, and fluorescent
• X-ray - diagnosing bone fractures and airport security scanner
• gamma ray - treats tumors and cancer through radio therapy it also sterilized surgical instruments
• radio/television signals are radio waves that are produced by making electrons vibrate
• Global Positioning System is a space based navigation system that provides geographical position and time information anywhere on the earth
• Magnetic Resonance Imaging is a medical imaging technique that uses powerful magnets, computers, and radio waves to make detailed pictures inside our body
• microwaves are used in satellite communication because it can penetrate through the earth`s atmosphere
• Terrestrial communication - a cellphone is a radio transmitter and a receiver that uses microwaves cellular phones depend on overlapping networking cells.
• cooking - the microwaves in a microwave oven penetrate and agitate the water molecules within the food.
• remote control uses led lights to transmit signals and control devices
• thermal imaging through infrared scanner - infrared scanner such as thermal imaging and thermal scanner are used to show the temperature variation of the body.
• blue and green indicate colder temperature while red and yellow indicate warmer
• night vision goggles use thermal imaging technology to capture infrared light emitted as heat by the objects in the field of view.
• one of the use of optical fibers in medicine is endoscope, a flexible tiny camera that is used to observe the internal parts of body
• security markings - sensitive documents such as bank notes, credit cards include a UV watermark that is only seen in UV emitting light.
• sterilization of water in drinking fountains- UV light disinfection is one water treatment system that can be used to remove microbiological contamination from the water.
• some washing powder contain fluorescent chemicals which glow in sunlight
• gamma ray treats tumors and cancer through a process called radio therapy