Reflection of Light at Plane and Curved Surfaces | Jamb(UTME)

Laws of Reflection

1. Reflection is the bouncing back of light when it hits a smooth surface.
2. The laws of reflection apply to all types of reflecting surfaces, including mirrors.
3. The first law of reflection states: The angle of incidence is equal to the angle of reflection $(\theta_i = \theta_r)$.
4. The second law of reflection states: The incident ray, reflected ray, and the normal all lie in the same plane.
5. These laws govern the behavior of light, ensuring predictable reflections.
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Applications of Reflection of Light

6. Mirrors are used in daily life for grooming, driving, and decoration.
7. Periscopes use plane mirrors to reflect light and enable viewing over obstacles.
8. Kaleidoscopes use multiple reflections to create beautiful patterns.
9. Reflection is utilized in rearview mirrors to provide a wide-angle view of traffic.
10. Dental mirrors reflect light to help dentists see inside the mouth.
11. Reflecting telescopes use mirrors to gather and focus light from distant celestial objects.
12. Solar cookers use concave mirrors to focus sunlight for cooking food.
13. Optical instruments, like microscopes and cameras, use reflection to direct light.
14. Reflection enhances visibility in safety mirrors and road signs at night.
15. The phenomenon is used in laser applications for precision surgeries and cutting tools.
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Formation of Images by Plane Mirrors

16. A plane mirror is a flat, smooth reflective surface.
17. The image formed by a plane mirror is always virtual (cannot be projected onto a screen).
18. The image is upright and of the same size as the object.
19. The image is laterally inverted, meaning left and right are swapped.
20. The distance of the image behind the mirror is equal to the distance of the object in front of the mirror.
21. Plane mirrors are used in households, vehicles, and optical instruments.
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Formation of Images by Concave Mirrors

22. A concave mirror is curved inward, like the inside of a spoon.
23. Concave mirrors can form both real and virtual images, depending on the object's position.
24. Real images are formed when light rays converge and can be projected on a screen.
25. Virtual images are formed when light rays diverge and cannot be projected on a screen.
26. When the object is far away, the image is real, inverted, and smaller.
27. At the focus, the image is a bright spot.
28. Between the focus and the mirror, the image is virtual, upright, and magnified.
29. Concave mirrors are used in shaving mirrors, headlights, and telescopes.
30. Ray diagrams show how light converges after reflection in concave mirrors.
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Formation of Images by Convex Mirrors

31. A convex mirror is curved outward, like the back of a spoon.
32. Convex mirrors always form virtual, upright, and diminished images, regardless of the object's position.
33. They provide a wide field of view, making them ideal for use as rearview mirrors.
34. The image appears closer to the mirror than it actually is.
35. Convex mirrors are used in security mirrors and road safety to monitor large areas.
36. Ray diagrams for convex mirrors show diverging rays appearing to originate from a focal point behind the mirror.
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Ray Diagrams for Plane, Concave, and Convex Mirrors

37. Ray diagrams are graphical methods to locate the position and size of an image.
38. For a plane mirror, draw an incident ray and reflect it at the same angle; the reflected ray appears to come from the image behind the mirror.
39. In a concave mirror, parallel rays converge at the focus after reflection.
40. If the object is beyond the center of curvature, the image is inverted and smaller.
41. For convex mirrors, incident rays diverge after reflection and appear to originate from a focal point behind the mirror.
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The Mirror Formula

42. The mirror formula relates the object distance $(u)$, image distance $(v)$, and focal length $(f)$:
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    $\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$
43. The mirror formula applies to concave and convex mirrors.
44. $u$ is always negative (measured against the direction of light).
45. $v$ is positive for real images and negative for virtual images.
46. $f$ is positive for concave mirrors and negative for convex mirrors.
47. By using the formula, you can calculate the image position, size, and type (real or virtual).
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Linear and Angular Magnification

48. Magnification is the ratio of the height of the image to the height of the object:
    
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    $M = \frac{Height of Image}{Height of Object} = \frac{v}{u}$
49. If $M > 1$, the image is magnified (larger than the object).
50. If $M < 1$, the image is diminished (smaller than the object).
51. In a plane mirror, magnification is always 1, as the image and object are the same size.
52. Angular magnification refers to the apparent enlargement of an object as seen through optical instruments like magnifying glasses.
53. Concave mirrors provide high magnification, useful for close-up tasks like shaving or makeup.
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Applications of Linear and Angular Magnification

54. High magnification is used in telescopes to observe distant celestial objects.
55. Magnification in microscopes allows scientists to study microorganisms.
56. Dentists use concave mirrors to magnify areas inside the mouth for better visibility.
57. Convex mirrors reduce magnification, providing a wide-angle view for security and safety.
58. Magnifying glasses and binoculars use convex lenses for linear magnification.
59. Optical instruments use angular magnification to enhance viewing angles.
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Practical Observations

60. Understanding the properties of mirrors helps in designing optical devices, improving safety, and enhancing visual experiences in daily life.
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