Applications of Electromagnetic Spectrum PDF

# Applications of Electromagnetic Spectrum ## Objectives: - Cite examples of practical applications of the different regions of EM waves, such as the use of radio waves in telecommunications. (S10-FE-Iic-d-48) - Discuss the practical uses of EM waves - Describe how EM waves can be used in daily ac...

# Applications of Electromagnetic Spectrum ## Objectives: - Cite examples of practical applications of the different regions of EM waves, such as the use of radio waves in telecommunications. (S10-FE-Iic-d-48) - Discuss the practical uses of EM waves - Describe how EM waves can be used in daily activities. ## Electromagnetic Waves - Transverse waves without a medium! (They can travel through empty space) - A drawing of a transverse wave is shown with the following labels: Wavelength, Crest, Direction of travel, Amplitude, Trough, Movement of water molecules - They travel as vibrations in electrical and magnetic fields. - Have some magnetic and some electrical properties to them. - A drawing showing a wave with vibrating magnetic and electric fields is shown with labels: Magnetic field, Electric field, Wavelength λ, Direction of propagation ## Speed of Electromagnetic Waves - Electromagnetic waves travel VERY FAST—around 300,000 kilometers per second (the speed of light). - At this speed, they can go around the world 8 times in one second. - A drawing of the earth is shown with an arrow representing the speed of an electromagnetic wave, going around the globe. ## Electromagnetic Spectrum - Name for the range of electromagnetic waves when placed in order of increasing frequency - An illustrated diagram shows the different electromagnetic waves in their place on the spectrum, along with their wavelengths and frequency: - Radio waves - Microwaves - Infrared Rays - Visible Light - Ultraviolet Rays - X-rays - Gamma rays ## Radio Waves - Have the longest wavelengths and lowest frequencies of all the electromagnetic waves. - A diagram of a radio wave is shown with the following labels: Wavelength (nm), Radio Wave, 10¹, 10³, 10⁶, 10⁹, 10¹², Mi ### Uses of Radio Waves: - **Global Positioning Systems (GPS):** Measure the time it takes a radio wave to travel from several satellites to the receiver, determining the distance to each satellite. - A drawing of a GPS displaying a map is shown, along with a drawing showing the way that a GPS works, using satellites. - **Radio:** Picks up radio waves through an antenna and converts it to sound waves. - Each radio station in an area broadcasts at a different frequency. - Number on the radio dial tells the frequency. - A drawing of a classic boombox radio is shown. - **Audio-frequency (AF) signals:** patterns of electric current variations - **Radio-frequency (RF):** high-frequency radio waves - **Frequency Modulation:** frequency of a wave that changes to match that of a signal. - A drawing of a boombox radio is shown. - **MRI (Magnetic Resonance Imaging):** Uses short radio waves with a magnet to create an image. - A drawing of an MRI machine is shown, along with a person undergoing an MRI. ## Microwaves - Have the shortest wavelengths and the highest frequency of the radio waves. - A diagram of a microwave wave has the following labels: (nm) Wave, 10^-10, 10^-8, 10^-6, 10^-4, 10^-2, 1, 10², 10⁴, 10⁶, 10⁸. A drawing of a microwave is shown. ### Uses of Microwaves: - **Microwave Ovens:** Waves transfer energy to the water in the food causing them to vibrate which in turn transfers energy in the form of heat to the food. - A drawing of a microwave oven with a chicken inside is shown. - **Radar (Radio Detection and Ranging):** A radar system consisting of an antenna, transmitter, and a receiver. Electromagnetic sensor used for detecting, locating, tracking, and recognizing objects of various kinds at considerable distances. - A drawing of a speed gun is shown. - **Terrestrial Communications:** Satellite television and cellphone communication. - A drawing of a satellite dish is shown, along with a mobile phone. ## Infrared Rays - Lies beyond the end of the visible light; it is emitted by all objects. - A diagram of an infrared wave shows the following labels: Microwave, 1 , 10², Infrared, 10⁴, 10⁶, UV, 10⁸, X-Ray, 10¹⁰, 10¹², - A drawing of a thermal image of a new born baby is shown. ### Uses of Infrared Rays: - **Thermogram:** A picture that shows regions of different temperatures in the body. Temperatures are calculated using infrared radiations given off. - A drawing of a person’s hand in infrared shows different temperatures, with the following labels: 7.5^o C and 1.3^o C - A drawing of a heat lamp shows the following labels: Heat lamps give off infrared waves, inframetrics - **Blue and Green in Infrared:** indicate regions of cooler temperature. - **Red and Yellow in Infrared:** indicate warmer temperatures. - A drawing of a cat in infrared is shown. - **Infrared Photographs:** Provides useful details of the vegetation of the Earth’s surface. - A drawing of a global infrared photograph with different colors indicating various vegetation is shown. - **Infrared Scanners:** Show the temperature variation of the body. - A drawing of a hand-held infrared scanner is shown, along with a drawing of people walking through an infrared scanner with a monitor displaying the temperature. - **Infrared Remote Controls:** Uses infrared rays. - A drawing of a remote control and a cassette player are shown. - **Night Vision Goggles:** Uses Infrared Rays. - A drawing of a person using night vision goggles is shown. - **Autofocus Cameras:** Uses infrared rays. - A drawing of two cameras is shown. ## Visible Light - Shorter wavelength and higher frequency than infrared rays. - Electromagnetic waves we can see. - **Longest Wavelength:** red light - **Shortest Wavelength:** violet (purple) light - A diagram of a visible light wave has the following labels: 10^-6, 10^-4, 10^-2, 1, 10², 10⁴, Visible. A drawing of the visible light spectrum is shown. - When light enters a new medium, it bends (refracts). Each wavelength bends a different amount allowing white light to separate into its various colors, ROYGBIV. - A drawing shows a beam of white light being refracted through a triangle as it changes to a rainbow, labelled ROYGBIV. ## Ultraviolet Rays - Shorter wavelength and higher frequency than visible light. - Carry more energy than visible light. - A diagram of a UV wave shows the following labels: ave, 10^-10, 10^-8, 10^-6, 10^-4, 10^-2, 1, 10², 10⁴, 10⁶, Infrared, UV, X-Ray, Gamma. A drawing of an ultraviolet machine is shown. ### Uses of UV Rays: - **Sun:** The main source of ultraviolet radiation, but there are also artificial sources of UV light. - **UV Lamps:** Used by banks to check the signature on a passbook. - A drawing of a UV lamp is shown, along with a drawing of a money checker. - **UV Radiation:** Used in sterilizing water from drinking fountains. - A drawing of two water-sterilizing devices using UV lights are shown. - **UV Radiation in Sunlight:** Produces Vitamin D in the skin and gives us the tanning effect. - A drawing of a person sunbathing and a person in a tanning bed is shown. - **Causes Your Skin to Produce Vitamin D:** Good for teeth and bones. - A drawing of a person sunbathing is shown, showing the production of Vitamin D. - **Too Much Causes Skin Cancer:** Suntan or sunscreen lotions serve as filters to protect the body from UV radiation. - A drawing of different skin cancers, along with a variety of sunscreens is shown. - **UV Radiation:** Used to kill bacteria. (Sterilization of equipment) - A drawing of a bunch of bacteria is shown. ## X-rays - Shorter wavelength and higher frequency than UV-rays. - Carry a great amount of energy. - Can penetrate most matter. - A diagram of an X-ray wave shows the following labels: 10^-10, 10^-8, 10^-6, 10^-4, 10^-2, 1, 10², 10⁴, 10⁶, Infrared, UV, X-Ray, Gamma Ray. A drawing of a skeleton is shown. - X-rays are produced using X-ray tubes. They are emitted when fast-moving electrons hit a metal target. - Wilhelm Conrad Roentgen discovered X-rays. - A drawing of Wilhelm Conrad Roentgen is shown, along with a drawing of the first X-ray of a hand that was ever taken. - **X-Ray Machines:** - A drawing of an older X-ray machine is shown. - A drawing of a modern X-ray machine is shown. ### Uses of X-Rays: - **Long Wavelength:** Bones and teeth absorb x-rays. (The light part of an x-ray image indicates a place where the x-ray was absorbed.) - A drawing of a dental x-ray and a picture of a bat taken with an x-ray are shown. - **Too Much Exposure Can Cause Cancer:** Lead vest at the dentist protects organs from unnecessary exposure. - A drawing of a person wearing a lead vest is shown. - **Short Wavelength:** Used by engineers to check for tiny cracks in structures. - A drawing of a piece of concrete is shown with the following labels: Concrete sample, 1 cm. A close up of the concrete showing cracks is illustrated with an adjacent x-ray of the concrete showing the cracks. ## Gamma Rays - Shorter wavelength and higher frequency than X-rays. - Carry the greatest amount of energy and penetrate the most. - A diagram of a Gamma ray shows the following labels: 10^-10, 10^-8, 10^-6, 10^-4, 10^-2, 1, 10², 10⁴, JV, X-Ray, Gamma Ray. A symbol representing gamma radiation is shown. - Used to treat cancer cells in the process called radiotherapy. - A drawing of a radiotherapy machine with someone laying on a table in it is shown. - Can be very harmful if not used correctly. - The Incredible Hulk was the victim of gamma radiation. - A drawing of the Hulk is shown, along with a bunch of gamma rays radiating around him. - Exploding nuclear weapons emit gamma rays. - A drawing of an atomic bomb explosion is shown. ## Brief Summary - **A:** All electromagnetic waves travel at the same speed (300,000,000 meters per second) in a vacuum. - **B:** They all have different wavelengths and different frequencies. - Long Wavelength --> Lowest Frequency - Short Wavelength –> Highest Frequency - The higher the frequency, the higher the energy. ## Wavestown - An illustrated cartoon showing the different types of electromagnetic waves, represented as buildings in a town called Wavestown. - **RAYSTV:** Radio waves. - **Wavesgrill:** Microwaves. - **PHOTOGRAPHIES:** Infrared rays. - **NUCLEAR MEDICING:** Gamma rays. - An illustrated diagram of a wave showing the following labels: 3cm, 0.3cm, 300m, 30m, 3mm, 0.3m, 30μm, 3μm, 0.3μm, 30nm, 3nm, 0.3nm, 30pm, 3pm, 0.3pm, 30fm, 3fm, 0.зfm, 23mm, 1, 2, 3, 4, 5, 6, 7. - **Antennas and Wave Propagation 1: Dr. Steven Stanford** - **Lecture 01**