grade-10-electromagnetic-spectrum ..pptx

POWERPOINT PRESENTATION

1. Instruction: Choose the letter of the correct answer. Pretest - Assessment 1. Which two waves lie at the ends of the visible spectrum? a. Infrared and Ultra-violet rays b. Radio waves and Microwaves c. Radio waves and X-rays d. X-rays and Gamma rays

2. 2. In the visible spectrum, which color has the longest wavelength? a. Blue b. Green c. Red d. Violet 3. Which property spells the difference between infra-red and ultra-violet radiation? a. Color b. Speed in vacuum c. Wavelength d. None of the above

3. 4. A certain radio station broadcasts at a frequency of 675 kHz. What is the wavelength of the radio waves? a. 280 m b. 324 m c. 400 m d. 444 m 5. What type of electromagnetic waves is used in radar? a. Infrared rays b. Microwaves c. Radio waves d. Ultra-violet rays

4. Directions: Show a pictures of different communication devices such as radio, cellphones, TV and medical equipment’s such as x -ray. Ask the uses of it.

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6. Direction: A group of students will arrange the scramble words to the correct terminologies and give a short description about the words.

7. Magneto electric CRUMPETS ELEECTROMAGNETIC SPECTRUM

8. DISAVOWERS RADIO WAVES

9. MMGAA YASR GAMMA RAYS

10. ERDANIFR YARS INFRARED RAYS

11. OASCIRWEMV MICROWAVES

12. Directions: Using an electromagnetic spectrum with the same group of students. Create a graphic organizer indicating the list of the wavelength, frequency and energy of each electromagnetic waves.

13. ELECTROMAGNETIC SPECTRUM

14. Direction: Explain the following questions that refers to the last activity we had.

15. Which among the EM waves has the highest frequency? _________________ Which among the EM waves has the lowest frequency? __________________Q3. The energy of an EM wave also depends on its frequency, which means waves with higher frequency has higher energy too. Which among the EM waves has the highest energy? __________________________ Which among the EM waves has the lowest energy? _____________________ What happens to the frequency of the electromagnetic waves as it progresses? Does the frequency of the EM waves increase or decrease as we go from radio wave to gamma ray? _______________________

16. ELECTROMAGNETIC SPECTRUM -JEALLEA S. AENLLE

17. Objectives At the end of this lesson, the students can: a. describe how electromagnetic wave is produced and propagate; b. compare the relative wave of different forms like wavelengths, frequencies, and energies of the different regions of electromagnetic spectrum; c. appreciate the useful application of electromagnetic waves in daily life activities

18. The concept known as  electromagnetic wave theory  originated with the work of James Clerk Maxwell and Heinrich Hertz . According to the electric and magnetic equations postulated by Maxwell, electromagnetic fields resemble a wave in both structure and action. Electromagnetic waves coincide with the measurement of the speed of light, making light an  electromagnetic wave  itself. ELECTROMAGNETIC WAVE THEORY

19. The electromagnetic wave theory states that any acceleration of an electric charge or change in the magnetic field produces radiation. This radiation can come in the form of either a wave or a particle. Velocity, wavelength and frequency are the factors associated with waves.

20. Electric field , an  electric  property associated with each point in space when  charge  is present in any form. The magnitude and direction of the electric field are expressed by the  value  of  E , called  electric field strength  or electric field intensity or simply the electric field. Magnetic fields - is a picture that we use as a tool to describe how the magnetic force is distributed in the space around and within something magnetic. arise from permanent magnets and electric charges in motion. Magnetic fields ultimately are the result of the motion of charges.

21. Basic properties of waves: Amplitude, wavelength, and frequency

22. All electromagnetic waves can travel through a medium but unlike other types of waves, they can also travel in vacuum. They travel in vacuum at a speed of 3X10 m/s and denoted as c the speed of light The wave speed, frequency, and wavelength are related by the following equation: v= λ f where v is the wave speed or c (speed of light) expressed in meters per second, the frequency f is expressed in Hertz and the wavelength A is expressed in meters

23. Since all the EM waves have the same speed and that is equal to the speed of light, as wavelength decreases, the frequency of the wave increases Through the years the advancement on the knowledge about electromagnetic waves led us to a modern technological world

24. Radio Waves Refers to electromagnetic radiation with wavelengths greater than about 0.1 m. Radio waves are commonly used for audio communications (i.e., for radios), but the term is used for electromagnetic waves in this range regardless of their application. Radio waves typically result from an alternating current in the wires of a broadcast antenna.   They cover a very broad wavelength range and are divided into many subranges, including microwaves, electromagnetic waves used for AM and FM radio, cellular telephones, and TV signals .    

25. Microwaves The highest-frequency electromagnetic waves that can be produced by currents in macroscopic circuits and devices. Their high frequencies correspond to short wavelengths compared with other radio waves hence the name “microwave.” Microwaves also occur naturally as the cosmic background radiation left over from the origin of the universe. Along with other ranges of electromagnetic waves, they are part of the radiation that any object above absolute zero emits and absorbs because of thermal agitation, that is, from the thermal motion of its atoms and molecules. Most satellite-transmitted information is carried on microwaves. Radar is a common application of microwaves.   Other application includes: WiFi , Bluetooth and RFID (radio frequency identification)  

26. Infrared Radiation “below red” generally produced by thermal motion, and the vibration and rotation of atoms and molecules. Electronic transitions in atoms and molecules can also produce infrared radiation. About half of the solar energy arriving at Earth is in the infrared region, with most of the rest in the visible part of the spectrum. Applications: Reconnaissance satellite, infrared lamps and remote controls

27. Visible light the narrow segment of the electromagnetic spectrum between about and about to which the normal human eye responds. Red light has the lowest frequencies and longest wavelengths, whereas violet has the highest frequencies and shortest wavelengths. Blackbody radiation from the Sun peaks in the visible part of the spectrum but is more intense in the red than in the violet, making the sun yellowish in appearance.  

28. Ultraviolet Radiation Ultraviolet means “above violet.” The electromagnetic frequencies of ultraviolet radiation (UV) extend upward from violet, the highest-frequency visible light. The highest-frequency ultraviolet overlaps with the lowest-frequency X-rays. The wavelengths of ultraviolet extend from down to about at its highest frequencies. Low-intensity ultraviolet has applications such as providing the energy to cause certain dyes to fluoresce and emit visible light, for example, in printed money to display hidden watermarks as counterfeit protection.  

29. X-rays have wavelengths from about to They have shorter wavelengths, and higher frequencies, than ultraviolet, so that the energy they transfer at an atomic level is greater.   The widest use of X-rays is for imaging objects that are opaque to visible light, such as the human body or aircraft parts

30. Gamma Rays The most penetrating nuclear radiation, the gamma ray, an extremely high-frequency electromagnetic wave. Gamma rays have characteristics identical to X-rays of the same frequency—they differ only in source. The name “gamma rays” is generally used for electromagnetic radiation emitted by a nucleus, while X-rays are generally produced by bombarding a target with energetic electrons in an X-ray tube. At higher frequencies, gamma rays are more penetrating and more damaging to living tissue.   They have many of the same uses as X-rays, including cancer therapy. Gamma radiation from radioactive materials is used in nuclear medicine