Electromagnetic Spectrum PowerPoint Presentation for Teachers/Students
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Here are some additional examples of practical applications of different regions of the electromagnetic spectrum: Radio waves: - Wireless communication (WiFi, Bluetooth, mobile networks) - Radio broadcasting Microwaves: - Satellite communication and television - Cell phone networks - Microwave ovens Infrared: - Infrared cameras and thermometers - TV remote controls - Infrared heating Visible light: - Lighting - Photography - Displays (LCD, LED screens) Ultraviolet: - UV lamps for curing, sterilization and counterfeit detection - Fluorescence microscopy - Dermatology treatments X-rays: -
Electromagnetic Spectrum PowerPoint Presentation for Teachers/Students
- 1. 1.A laser emits light of frequency 4.74 x 1014 Hz. What is the wavelength of the light in m? 2.A certain electromagnetic wave has a wavelength of 6.25 x 10-7 m. (a) What is the frequency of the wave? (b) What region of the electromagnetic spectrum is it found?
- 3. GUESS WHAT?
- 4. R A D I O VALERA
- 5. O V E N
- 6. R E M O T E
- 7. L A S E R
- 8. S U N T A N L A M P
- 9. R A YX
- 10. G A M M T R A C E A R
- 13. Radio Waves • Radio waves have the longest wavelength in the electromagnetic spectrum. They are produced by making electrons vibrate in an antenna. They are used to transmit sound and picture information over long distances.
- 15. Microwaves •Microwaves have smaller wavelengths than radio waves. They are used in satellite communications, radar, television transmission and cooking.
- 16. Infrared • Infrared radiation lies beyond the red end of the visible light. It is emitted by all objects. The amount and wavelength of radiation depend on temperature. Below 500oC, an object emits only infrared radiation. Above 500oC, an object glows and emits both infrared and some visible light. • Our bodies radiate infrared and under infrared camera or a night vision goggle, our images appear in variety of colors. The differences in color determine the differences in temperature. For example, shades of blue and green indicate regions of colder temperature; and red and yellow indicate warmer temperature.
- 18. Visible Light • When white light passes through a prism, it is separated into its constituent colors: the red, orange, yellow, green, blue, indigo and violet. These colors do not distinctly separate but they continuously change from red to violet. Red color has the longest wavelength from among these colors and violet has the shortest.
- 19. Visible Light • Our eyes are sensitive to electromagnetic waves of wavelengths that ranges from 4x10- 7 m to 7x10-7 m. This is the range of wavelengths of white light. Thus, the spectrum of white light is therefore called the visible spectrum.
- 20. Ultraviolet Radiation • Ultraviolet radiation lies just beyond the violet end of the visible spectrum. Ultraviolet waves have shorter wavelengths than the visible light and carry more energy.
- 21. Some Uses of UV Radiation • The sun is our main source of ultraviolet radiation but there are also artificial sources of UV light. Ultraviolet radiation in UV lamps are used by banks to check the signature on a passbook. The signature is marked on the passbook with fluorescent ink. It becomes visible when viewed under an ultraviolet lamp. These lamps are also used to identify fake banknotes.
- 22. Some Uses of UV Radiation • Ultraviolet radiation in sunlight produces vitamin D in the skin and gives us tanning effect. But since UV rays have high energy, it could be harmful to some extent. It could burn the skin and hurt our eyes. Overexposure to UV radiation may cause skin cancer. Suntan or sunscreen lotions serve as filters to protect the body from ultraviolet radiation.
- 23. X-Rays • X-rays come just after the ultraviolet rays. They are of shorter wavelength but carries higher energy than the UV. • X-rays are produced using an X-ray tube. They are emitted when fast moving electrons hit a metal target. X-rays were discovered by Wilhelm Conrad Roentgen in 1895. • Long wavelength X-rays can penetrate the flesh but not the bones. They are used in X-ray photography to help doctors look inside the body. They are useful in diagnosing bone fractures and tumors.
- 24. Gamma Rays • Gamma rays lie at the other end of the electromagnetic spectrum. They are shortest in wavelength and highest in frequency. They carry the highest amount of energy, thus, they are more dangerous. Gamma rays are emitted by stars and some radioactive substances. They can only be blocked with lead and thick concrete. • Gamma rays are very strong that they can kill living cells. Gamma rays are used to treat cancer through the process called radiotherapy. They are also used for sterilization of drinking water.
- 25. EM Wave Application of EM Wave (Lower/Higher) Energy (Low/High) Frequency (Short/Long) Wavelength ____1. Radio Wave a. Remote ____2. Microwave b. X-Ray ____3. Infrared c. Gamma Tracer ____4. Visible Light d. Sun Tan Lamp ____5. Ultraviolet Rays e. Microwave Oven (Lower/Higher) Energy (Low/High) Frequency (Short/Long) Wavelength ____6. X-Rays f. Laser ____7. Gamma Rays g. Radio ACTIVITY 10 – Electromagnetic Spectrum
- 26. EM WAVE CHARACTERISTICS OF EM WAVE APPLICATION OF EM WAVE Radio Waves Microwaves Infrared Visible Light Ultraviolet Rays X-Rays Gamma Rays ACTIVITY 10 – Electromagnetic Spectrum
- 29. ANSWERS
- 30. 1. Which of the following statements states the relationship between wavelength and frequency in the electromagnetic spectrum? A.As the wavelength increases, the frequency increases. B.As the wavelength decreases, the frequency decreases. C.As the wavelength increases, the frequency decreases. D.As the wavelength decreases, the frequency remains constant.
- 31. 2. Which electromagnetic wave is used in remote controls? A.Infrared B.Radio waves C.Microwaves D.Visible light
- 32. 3. Which electromagnetic waves have the shortest wavelengths and highest frequencies? A.X-rays B.Gamma rays C.Radio waves D.Ultraviolet rays
- 33. 4. How do you call electromagnetic waves that you can see? A. X-rays B. Infrared rays C. Microwaves D. Visible light
- 34. 5. Which region of the electromagnetic spectrum has greater energy level than x-rays? A. Infrared B. Radio waves C. Gamma rays D. Ultraviolet rays
- 35. Show me a thumb-up sign if you say YES to the following behaviors and thumb-down sign if you say NO. 1. I showed cooperation during group activities. 2. I listened to the views of my classmates during discussions. 3. I find the lesson in science boring. 4. I enjoyed the activities prepared for the lesson. 5. I am glad I learned new ideas in science in today’s lesson.
- 36. ASSIGNMENT: Cite more examples of practical application of the different regions of the electromagnetic spectrum.
Editor's Notes
- #2: 1.) 6.32 E-7 m 2.) (a) 4.8E14 Hz (b) Visible Light
- #11: tracers are used to investigate a patient's body without the need for surgery. Gamma emitters and sometimes beta emitters are used. This is because gamma rays and beta particles can pass through skin, whereas alpha particles cannot.
- #16: In a microwave oven, foods absorb certain microwave frequencies very strongly. The microwaves penetrate the food being heated. It will agitate the water molecules within the food, thus creating molecular friction which then produces heat that will cook it.
- #18: Infrared remote controls are used in TVs, video, cassette recorders, and other electronic appliances. Some night-vision goggles use IR
- #24: All X-rays are dangerous because they can damage healthy living cells of the body. This is the reason why frequent exposure to X-rays should be avoided. Too much exposure to X-rays can damage body tissues and can cause cancer.
- #28: Venus and Mars Show