GRADE10-1-2NDQ.pptxdsafqwfwqhg2qwjh2werjhwj

awfqfqwqyhyhq

1. Different Forms of EM waves

2. Waves Waves are disturbances that carry energy from one place to another. pulse wave is a sudden disturbance in which only one wave or a few waves are generated, 

3. Mechanical Waves Are waves that require a medium to transfer energy and cannot travel through a vacuum. Medium is a material that moves energy from one location to another( solid liquid and gas)

4. Sound Waves Ocean Waves

5. Electromagnetic Waves Are waves that do not require a medium to travel through and can travel through a vacuum . Vacuum is an empty space or free space

6. Visible L ight Radio Waves X-ray

7. How EM waves Produced ? An electron is a negatively charged subatomic particle that can be either bound to an atom or free (not bound). They are produced by accelerating charged particles. When a charged particle oscillates, it creates oscillating electric and magnetic fields that propagate as an EM wave. 

8. 4 Properties of EM waves They do not require any material or medium to propagation The produced by accelerated or oscillating charge.

9. Properties of EM waves EM waves travels to a vacuum or outer space at the speed of 3x10⁸ m/s

10. Can we change the speed of light? No because speed of light is ultimate speed limit

11. Can we slower speed of light?

12. 4. EM wave, such as light , travel slower to through glass and water. Dispersion of light is  the phenomenon where white light separates into its constituent colors  . Refraction of light in water is the bending of light rays as they pass from one medium (like air) into another (like water). This bending happens because light travels at different speeds in different mediums, and it changes direction when the speed changes. 

13. Reflection What is importance EM waves in our everyday life ? How EM waves produced?(explain) What is the difference between EM waves and Mechanical waves(explain)

14. PROPONENTS OF ELECTROMAGNETIC WAVES

15. ELECTRICITY MAGNETISM

16. 16th to the 18th centuries or what we called the Revolutionary Period of Scientific invention and discovery or (Scientific Revolution). The connection between the electricity and magnetism discovered.

17. Oersted Ampere Faraday Maxwell Hertz PROPONENTS OF ELECTROMAGNETIC WAVES

18. was a Danish physicist and chemist who discovered that electric current in a wire can deflect a magnetized compass needle. HANS CHRISTIAN OERSTED (1820)

19. André-Marie Ampère was a French physicist and mathematician who produced a magnetic attraction and repulsion without the use of any magnets , all of it was generated by electricity. He coined the term “Electrodynamics” ANDRE MARIE AMPERE 1820

20. Michael Faraday was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying “ ELECTROMAGNETIC INDUCTION ”. MICHAEL FARADAY 1831

21. The Law of Induction -also known as  Faraday's Law of Induction , states that  a changing magnetic field produce a voltage (electromotive force or EMF) in a nearby circuit .   INDUCTION - refers to  the process of generating an electromotive force (EMF) or voltage.

22. COIL GALVANOMETER- is one of the instruments for measuring electrical current   HOLLOW METAL TUBE MAGNET ELECTROMAGNETIC INDUCTION-is a current produced because of voltage production due to a changing magnetic field.

23. James Clerk Maxwell was a Scottish physicist best known for his formulation of electromagnetic theory. James Clerk Maxwell 1864

24. Maxwell's Equations: This set of four fundamental equations mathematically describes the relationship between electric and magnetic fields and their sources (charges and currents). Ampère's Law with Maxwell's Addition Faraday's Law of Induction Gauss's Law for Magnetism Gauss's Law for Electricity

25. According to Maxwell’s Theory James Clerk Maxwell's theory predicted that a changing electric field, even in the absence of electric currents, can produce a magnetic field . So that Maxwell predicted the existence of EM waves.

26. According to Maxwell EM waves travel at the speed of light and light is a form of an Electromagnetic wave.

27. A German physicist Heinrich Hertz discovered radio waves, a milestone widely seen as confirmation of  James Clerk Maxwell’s electromagnetic theory and which paved the way for numerous advances in communication technology. Heinrich Hertz 1887

28. Spark generator Metallic Ring Antenna

29. Oersted- A moving charge creates magnetic field. Ampere- Magnetism can be produced by electricity Faraday- A changing magnetic field produce electricity Maxwell- Predicted the existence of EM waves Hertz- discovered radio waves PROPONENTS OF ELECTROMAGNETIC WAVES

30. ELECTROMAGNETIC SPECTRUM

31. Crest : The highest point of a wave  Trough : The lowest point of a wave  Wavelength : The distance between two identical points on a wave, such as crest to crest or trough to trough  Amplitude : The distance between the resting point and the crest or trough PARTS OF WAVES

32.  The number of waves passing a fixed point in a specified period of time. It refers to how fast the wave vibrates or the number of cycles per second. Frequency

33. ELECTROMAGNETIC SPECTRUM The electromagnetic spectrum is a continuum of electromagnetic waves arranged according to frequency and wavelength. It is the gradual progression in the waves of lowest frequencies to the highest frequencies. The EM spectrum includes radio waves , microwaves , infrared rays , visible light , ultraviolet , x-rays , and gamma rays .

34. ELECTROMAGNETIC WAVES APPLICATION

35. Radio waves Radio waves  are at the lowest range of the electromagnetic spectrum, with frequencies of up to about 30 billion hertz, or 30 gigahertz (GHz), and wavelengths greater than about 0.4 inch (10 millimeters). Radio is used primarily for communications, including voice, data and entertainment media.

36. Uses of Radio waves • Used for communications that is why the thing in your car is called a radio. • Used to broadcast television signals. • Used to transmit sound and picture information over long distances.

37. Microwaves Microwaves fall in the range of the electromagnetic spectrum between radio and IR. They have frequencies from about 3 GHz to 30 trillion hertz, or 30 terahertz (THz), and wavelengths of about 0.004 to 0.4 inch (0.1 to 10 mm) . Microwaves are used for high-bandwidth communications and radar, as well as for a heat source for microwave ovens and industrial applications.

38. Uses of Microwaves Used for satellite communications. Used in satellite communications, Radar(Radio Detection and Ranging), television transmission, and cooking. Since microwaves are not that different from radio waves, they have also been used for communications, especially for extending TV signals to larger distances.

39. I nfrared/ Infrared radiation Infrared is in the range of the electromagnetic spectrum between microwaves and visible light. IR has frequencies from about 30 to 400 THz and wavelengths of about 0.00003 to 0.004 inch (740 nanometers to 100 micrometers). IR light is invisible to human eyes, but we can feel it as heat if the intensity is sufficient.

40. Uses of I nfrared/ Infrared radiation • Infrared photographs taken from a satellite with special films provide useful details of the vegetation on the Earth’s surface. • Infrared scanners are used to show the temperature variation of the body. This can be used for medical diagnosis. • Infrared remote controls are used in TVs, video, cassette recorders, and other electronic appliances. • Some night-vision goggles use IR.

41. Visible light Visible light is found in the middle of the electromagnetic spectrum, between IR and UV. It has frequencies of about 400 to 800 THz and wavelengths of about 0.000015 to 0.00003 inch (380 to 740 nanometers). More generally, visible light is defined as the wavelengths that are visible to most human eyes

42. The segment of the electromagnetic spectrum that human eyes can see is known as the visible light spectrum

43. Violet  - shortest wavelength, around 380-450 nanometers with highest frequency. They carry the most energy. Indigo  - 420 - 440 nm Blue  - 450 - 495 nm Green  - 495 - 570 nm Yellow  - 570 - 590 nm Orange  - 590 - 620 nm Red  - longest wavelength, at around 620 - 750 nanometers with lowest frequency

44. ULTRAVIOLET Ultraviolet light is the range of the electromagnetic spectrum between visible light and X-rays. It has frequencies of about 8 × 10 14  to 3 x 10 16  Hz and wavelengths of about 0.0000004 to 0.000015 inch (10 to 380 nanometers). UV light is a component of sunlight, but it is invisible to the human eye. It has numerous medical and industrial applications, but it can damage living tissue

45. Uses of X-ray They are used in X-ray photography to help doctors look inside the body. They are useful in diagnosing bone fractures and tumors. X-rays can penetrate even through metals. They are used in industry to inspect welded joints for faults.

46. Gamma Ray Gamma-rays  are in the range of the spectrum above soft X-rays. Gamma-rays have frequencies greater than about 10 18  Hz and wavelengths of less than 4 × 10 −9  inch. Gamma radiation causes damage to living tissue, which makes it useful for killing  cancer  cells when applied in carefully measured doses to small regions. Uncontrolled exposure, though, is extremely dangerous to humans.

47. Uses of Gamma Ray 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.