Q2L1-EM Waves PDF

Let us Pray Hello! I am Sir Prince John S. Layno, you can call me sir Layno. It’s nice meeting you today! Attendance Check! Reminders: pick pieces of trash within your area. straighten your seating arrangement; and keep your belongings properly organized. Classroom Rule No. 1...

Let us Pray Hello! I am Sir Prince John S. Layno, you can call me sir Layno. It’s nice meeting you today! Attendance Check! Reminders: pick pieces of trash within your area. straighten your seating arrangement; and keep your belongings properly organized. Classroom Rule No. 1 Raise your hand before speaking or leaving your seat. Classroom Rule No. 2 Listen attentively and follow direction. Classroom Rule No. 3 Respect your classmates and your teachers. Classroom Rule No. 4 Arrange your belongings and clean your area.  Reviewing Previous Lesson Pre-assessment Choose the capital letter of the best answer and write it on your 1/4 sheet of intermediate paper. 1. How are electromagnetic waves produced? A. Any disturbance B. Current C. Vibrating charge D. Voltage source 2. In the electromagnetic wave, what is the direction of the propagation of the wave? A. Always to the right B. Cannot be determined C. Parallel to the electric & magnetic field directions D. Perpendicular to the electric and magnetic field directions 3. Which of the following forms of electromagnetic waves has the widest frequency range? A. Microwave B. Radio waves C. Ultraviolet D. X-ray 4. What happens to the frequency of the electromagnetic wave if its wavelength increases? A. It decreases. B. It increases as well. C. It remains the same. D. None of the above. 5. What is the speed of the electromagnetic wave in a vacuum? A. Zero B. Always the same as the speed of light C. Changing depending on the value of its wavelength D. none of the above 6. Who contributed in developing equations that showed the relationship between electricity and magnetism? A. André-Marie Ampere B. Heinrich Hertz C. James Clerk Maxwell D. Michael Faraday 7. Who showed the experimental evidence of electromagnetic waves and their link to light? A. André-Marie Ampere B. Heinrich Hertz C. James Clerk Maxwell D. Michael Faraday 8. Which type of wave has the shortest wavelength? A. Gamma ray B. Microwave C. Ultraviolet D. X-ray 9. What is the other term for electromagnetic waves? A. Electric waves B. Longitudinal waves C. Mechanical waves D. Transverse waves 10. All EM waves have the same speed. A. True B. False 11. Which of the following correctly lists electromagnetic waves in the order from the longest to the shortest wavelength? A. Gamma rays, ultraviolet, infrared, microwaves B. Microwaves, ultraviolet, visible light, gamma rays C. Radio waves, infrared, gamma rays, ultraviolet D. Radio waves, infrared, visible light, X-rays 12. How does the wavelength of infrared differ from the wavelength of ultraviolet waves? A. Longer B. Shorter C. The same D. None of the above 13. What is the main difference between a radio wave and a light wave? A. Speed B. Wavelength C. Both A and B D. None of the above 14. Which of the following is NOT an electromagnetic wave? A. Infrared B. Light C. Sound D. Radio 15. What is the frequency range of UV radiation? A.3.5x10 9 –3x10 Hz 11 B. 3.5x10 – 4x10 Hz 11 14 C. 7.5x10 – 3x10 Hz 14 16 D. 7.5x10 – 3x10 Hz 16 19  Answer Key 1. A 6. C 11. D 2. D 7. B 12. A 3. D 8. A 13. B 4. A 9. D 14. C 5. B 10. A 15. C Why are these things important? Electromagnetic Waves  Learning Objectives At the end of the lesson, we should be able to: a. describe how an electromagnetic (EM) wave is produced and propagated; b. find out who are the significant proponents on the formulation of electromagnetic theory; and c. compare the relative wavelengths of different forms of electromagnetic waves.  Yes! Yes! Commander Game mechanics: students should follow the teacher’ s request or command and the last student to enact will be required to answer the questions.  True or False Say TRUE if the statement is correct, and FALSE if it is not. Provide a brief explanation for your answer based on the image provide. 1. Electromagnetic waves transfer energy through a vacuum. 2. The crest is the highest point in a wave.  3. Trough is the distance from the midpoint to the highest or lowest point of a wave. Revisit Waves are Mechanical Waves disturbances that require a medium (particles) to travel carry energy from through. one place to Non-mechanical Waves another. Do not require a medium to travel through and can travel through a vacuum. MECHANICAL WAVES: Vibrations occur parallel to the Longitudinal direction the wave travels Have regions of compression and rarefaction moving through the medium. Ex: Sound waves direction of direction of vibration wave propagation compression rarefaction MECHANICAL WAVES: Vibrations occur at right angles/ perpendicular to Transverse the wave’s direction. Ex: Surface water waves direction of vibration direction of wave propagation Nature and Properties of Electromagnetic Wave  Nature of Electromagnetic Waves EM waves are produced by a charge that changes its direction or speed. It is caused by any disturbances that caused this charge to vibrate. Ex: electron  Nature of Electromagnetic Waves 1. Transverse Waves - The electric and magnetic field oscillate perpendicularly to each other and to the direction of the wave propagation.  Nature of Electromagnetic Waves 2. Self-propagating - Changing electric field generates a magnetic field, and changing magnetic field generates electric fields. This allows the wave to propagate without a medium.  Nature of Electromagnetic Waves 3. Carry energy - EM waves do not carry energy by causing matter to vibrate. It’s the electric and the magnetic field.  Nature of Electromagnetic Waves 4. No medium required - Can travel through vacuum but does not mean it cannot travel to a medium. Ex: light.  Nature of Electromagnetic Waves 5. Travel so fast - Can travel in a vacuum at a speed of 299,792,458 m/s or approx. 300,000,000 or 3x10 m/s and 8 denoted as c , the speed of light. Can travel slower through matter.  Properties of EM Waves They are produced by accelerated or oscillating charge. They do not need any material or medium for propagation They travel in free space at the speed of light (3x10 m/s). 8 Group 1 Group 2 Group 3 Group 4 Group 5 Watiwat Antipuesto Briones Delos Acob Quiambao Grecia Talib Reyes Perono Legas Dela Cruz Ledda Lagmay Ming Pon-an Hinong Gamiao Gadayan Tabares Asena Duruin Daras Caspe Genotiva Pamposa Penuela Palaguyan Limbungan Saldana Tingson Lamalan Estudillo Jimenez Mosnge Orfrecio Hizon Unscramble Me! Unscramble the words in Box B and match t h e m t o t h e appropriate blanks in Box A to complete the statements. Answer for 3 minutes.  Answer Key 1. Magnetic Field 3. EM 5. Objects 2. Electric Field 4. Outward Proponents on the Formulation of EM Wave Theory  What is EM Wave Theory? It explains how electric and magnetic fields interact to form waves that can travel through space. These waves carry energy and include the waves in EM spectrum.  Electric fields are invisible forces that push or pull charged particles. Magnetic fields are the forces that act on magnetic materials or moving charged particles. Changes of field create each other and move together as a wave. Hans Christian Oersted (1820) When electric current flows through a wire, it creates a magnetic field around it.  Compass Needle Experiment Placed a needle compass near current- carrying wire and needle of the compass moved.  Andre-Marie Ampere (1820) Studied how 2 parallel current- carrying wires attract or rep el each other Interaction of Parallel Currents Showed that current in wires create magnetic forces, and direction of force depends on the current’s direction Michael Faraday (1831) His electromagnetic induction showed that a changing magnetic field can generate electric current.  Electromagnetic Induction Moved magnet in and out a coil wire and it induced an electric current in a wire. This showed magnetism produce electricity.  James Clerk Maxwell (1864) He discovered that when magnetic field changes, it creates an electric field, and when electric field c h a n ge s , i t c re ate s a magnetic field.  Foundation of EM Wave Theory He developed a Maxwell’s equation using the works of Oersted, Ampere, and Faraday. It shows that electric & magnetic fields creates waves that travel through space at the speed of light which suggests that light is an EM wave itself. Heinrich Hertz (1888) He proved that electromagnetic waves ex iste d by cre at i n g them in the lab and detecting them  Generation & Detection of EM waves Used spark gap to create radio wave and showed these waves could travel through space, be reflected and interfere each other EM Waves: Frequencies and Wavelengths  Parts of a Wave Crest crest Otherwise known as the peak, the highest point of a wave Rest or Equilibrium Position The undisturbed position of rest the particles if they do not position vibrate trough Trough The lowest point of a direction of wave propagation wave  PARTS OF A WAVE: Wavelength It is a set distance that represents the full cycle of a wave. It can one wavelength be measured from crest to crest, from trough to trough, or any two consecutive points in the wave cycle. direction of The unit for wavelength wave travel (λ, Greek letter lambda) is metres (m). PARTS OF A WAVE: Frequency It is the number of low frequency waves passing a specific point per second. The unit of frequency is hertz high frequency (Hz), which is equal to 1 cycle per second (1/s). PARTS OF A WAVE: Amplitude It is the maximum disturbance from amplitude the crest of the wave from its rest position. It represents the wave's height. direction of The unit for wave travel amplitude (A) is metres (m).  EM waves are arranged in order of frequencies and wavelengths, known as electromagnetic spectrum. Waves with longest wavelengths have lowest frequencies while those have shortest wavelengths have highest frequencies. The amount of energy also increases as frequency increases.  Em waves are defined by the energy carried by their photons, which is a bundles of wave energy. In terms of energy and frequency: Gamma rays= highest energy= highest frequency Radio Waves= lowest energy= lowest frequency In terms of wavelength: Gamma rays= like nuclei of an atom Radio waves= like football field  Calculating Velocity of a Wave The velocity of a wave depends on its frequency and wavelength. When calculating wave velocity we use the following formula: wave velocity in m/s = frequency in Hertz or 1/s × wavelength in m  Sample Problem 1 Given: Solution: λ = 2.0 x 101 m 3x108 m/s c = 3 x 108 m/s f= 2.0x101 m Find: f = 1.5x108-(-1) s f = ? Hz or 1/s f = 1.5x107 s or Hz General Equation: c The wave has a frequency v = c= fλ f= λ of 15,000,000 Hz  Sample Problem 2 Given: Solution: λ = 5 x 10-7 m 3x108 m/s c = 3 x 108 m/s f= 5x10-7 m Find: f = 0.6x108-(-7) s f = ? Hz or 1/s f = 6x1014 s or Hz General Equation: c The wave has a frequency of v = c= fλ f= 600,000,000,000,000 Hz λ  Concept Web With the same groupings, create a concept web that illustrates the contributions of the scientists listed below, based on the information you learned earlier. Write your answers on the back of the worksheet.  Problem-solving Assume that the waves propagate in a vacuum. Solve the sample problems on the worksheet provided. Each correct answer is worth 5 points.  Concept Web Activity Ampere · Discovered that electric currents can attract or repel one another. Answer Key · Formulated the Ampere’s Law of Electromagnetism. · Contributed to the best definition of electric current of his time Faraday · Discovered electromagnetic induction. · Introduced the concept of a field in physics to describe electromagnetic interactions. · Made fundamental contributions to the electromagnetic theory of light. Hertz · Proved the existence of radio waves by applying Maxwell’s theories. · Used a spark gap and rods as antennas to detect radio waves. · Showed that radio waves possess all the properties of EM waves. · The unit of frequency for radio waves, “Hertz,” is named in his honor. Maxwell · Developed the field theory explaining electromagnetic waves. · Proposed that light is an electromagnetic wave. · Deduced the finite velocity of light. · Demonstrated that a changing magnetic field induces an electric field and vice versa. Oersted · Discovered that electric currents can detect a magnetized compass needle. · Inspired the development of electromagnetic theory through this discovery. Problem-Solving Activity 1. f= 1.5x107Hz 2. f= 6x1014Hz  Think-Pair-Share Find a partner and answer in a short paragraph. Write your names and answers on a ¼ sheet of intermediate paper. 1. How is an electromagnetic spectrum organized in terms of its frequency and wavelength? 2. What happens to the wavelength of an electromagnetic wave if its frequency increases?  Assessment Prepare 1 whole sheet of intermediate pad. Write your name and section Instructions: 1. Inside your house, think of 4 devices and appliances that you use every day. 2. Name 4 objects that you see that can produce electromagnetic waves. 3. Write the uses/applications of the objects that you have listed. 4. Answer in 5 minutes. Object Applications Form of EM wave 1. Cellphone Used for telecommunication, watching, Radio wave gaming, etc. Visible Light 2. 3. 4. Instructions: On the other side of the paper, answer the following questions briefly and concisely in 5 minutes. Show your solution for item 3. 1.How do electromagnetic waves play an important role in your life? 2. H o w d i d t h e E l e c t r o m a g n e t i c Wa v e T h e o r y r e s u l t i n t h e advancement of a modern technological world? 3.What is the frequency of a microwave that has a wavelength of 1.5x102 m? Given: v = c = 3x108 m/s (constant) λ = 1.5x102 m f =?  Summary A wave is a disturbance that transfers energy. James Clerk Maxwell formulated the Electromagnetic Wave Theory which says that an oscillating electric current are capable of radiating energy in the form of electromagnetic waves. Heinrich Hertz discovered the radio waves. Hertz is the unit used to measure the frequency of waves. An electromagnetic wave comprises of an electric field and a magnetic field at right angles to each other and to the direction of motion of the wave. Electromagnetic waves can travel through a vacuum because they do not require matter to exist.  Electromagnetic waves are produced by a charge that is changing direction or speed. All electromagnetic waves travel at the same speed in a vacuum of 3x108 m/s. The EM waves are often arranged in the order of wavelength and frequency in what is known as the electromagnetic spectrum. Frequency describes how many waves per second a wavelength produces. Wavelength measures the length of individual wave in meters. Waves with longest wavelengths have the lowest frequencies. Waves with the shortest wavelengths have the highest frequencies. Post-assessment Choose the capital letter of the best answer and write it on your 1/4 sheet of intermediate paper. 1. Which of the following correctly lists EM waves in the order from the longest to the shortest wavelength? A. Gamma rays, ultraviolet, infrared, microwaves B. Microwaves, ultraviolet, visible light, gamma rays C. Radio waves, infrared, gamma rays, ultraviolet D. Radio waves, infrared, visible light, X-rays 2. How does the wavelength of infrared differ from the wavelength of ultraviolet waves? A. Longer B. Shorter C. The same D. None of the above 3. What is the main difference between a radio wave and a light wave? A. Speed B. Wavelength C. Both A and B D. None of the above 4. Which of the following is NOT an electromagnetic wave? A. Infrared B. Light C. Sound D. Radio 5. What is the frequency range of UV radiation? A.3.5x10 9 –3x10 Hz 11 B. 3.5x10 – 4x10 Hz 11 14 C. 7.5x10 – 3x10 Hz 14 16 D. 7.5x10 – 3x10 Hz 16 19 6. Who contributed in developing equations that showed the relationship of electricity and magnetism? A. André-Marie Ampere B. Heinrich Hertz C. James Clerk Maxwell D. Michael Faraday 7. Who showed the experimental evidence of electromagnetic waves and their link to light? A. André-Marie Ampere B. Heinrich Hertz C. James Clerk Maxwell D. Michael Faraday 8. Which type of wave has the shortest wavelength? A. Gamma ray B. Microwave C. Ultraviolet D. X-ray 9. What is the other term for electromagnetic waves? A. Electric waves B. Longitudinal waves C. Mechanical waves D. Transverse waves 10. All EM waves have the same speed. A. True B. False 11. How are electromagnetic waves produced? A. Any disturbance B. Currents C. Vibrating charge D. Voltage source 12. In the electromagnetic wave, what is the direction of the propagation of the wave? A. Always to the right B. Cannot be determined C. Parallel to electric and magnetic field directions D. Perpendicular to the electric and magnetic field directions 13. Which of the following forms of electromagnetic waves has the widest frequency range? A. Microwave B. Radio waves C. Ultraviolet D. X-ray 14. What happens to the frequency of the electromagnetic wave if its wavelength increases? A. It decreases. B. It increases as well. C. It remains the same. D. None of the above. 15. What is the speed of the electromagnetic wave in a vacuum? A. Zero B. Always the same as the speed of light C. Changing depending on the value of its wavelength D. none of the above  Assignment Instructions: Draw the EM spectrum on a long bond paper from having the highest to lowest value per category: wavelength, frequency, and energy. Refer to the rubrics provided. Submission of the assignment will be at the next meeting.