1.
Light is the visible region of electromagnetic radiation spectrum
2.
Its wavelength ranges from 400-700 nanometers
3.
Its frequency ranges from 430-750 terahertz
4.
It can be dispersed into its constituent colors by prism.
5.
it was considered to be a stream of particles before the end of 19th
century
6.
Isaac Newton is behind the particle theory of light
7.
Isaac Newton believed that particles leaves object and bring about the sense of
light upon entering the eyes.
8.
Particle theory of light only survives the 18th century.
9.
In the particle theory of light, the particles were either emitted from the
objects or emanated from the eye of the viewer.
10. Light
is in form of a wave motion according Christian Huygens
11. Thomas
young demonstrate that light can interfere like other waves.
12. Light
is a high frequency electromagnetic radiation according to Maxwell.
13. Wave
theory of light only survives the 19th century.
14. Maxwell,
Christian Huygens, Thomas Young and Hertz are behind the wave theory of light.
15. Photoelectric
effects violate the wave theory of light.
16. Compton
scattering violate the wave nature of light.
17. Interference
of light wave violates the particle theory of light.
18. Diffraction
of light violates the particle theory of light.
19. Light
can exist as wave and as particle according to Louis de-Broglie, hence the wave
particle duality.
20. Wave
–particle duality or dual nature of light is the existence of light as both
wave and particles.
21. Reflection
is the bouncing back of light from a surface.
22. At
all time the incident angle and the reflection angle are equal
23. The
ratio of the sine function of the incident angle to that of the refraction
angle is a constant called the refractive index.
24. The
refractive index is unique for all substance and mediums.
25. Specula
reflection occur on perfectly smooth surface
26. Diffused
reflection occur reflection occur from a rough surface.
27. For
plane mirrors, image distance is equal to objet distance.
28. For
plane mirrors image formed are virtual
29. Virtual
image are image formed when no actual ray interest to form the image
30. Virtual
images cannot be projected on a screen.
31. Magnification
is the increase in the size of virtual object in plane mirror.
32. Total
internal reflection only our when the critical angle is greater than 90 and the
refractive index of the second medium is less than that of the first
33. The
apparent dept of an object is less than the real depth.
34. When
light move from one medium to another its frequency remains the same while the
velocity and wavelength changes.
35. The
speed of light in vacuum is the greatest speed it can have.
36. The
ratio speed of light in vacuum to that in any other medium is called the
refractive index.
37. In
specula reflection the incident ray, the reflected and normal all lie in the
same plane.
38. When
light enters a medium with, it may be absorbed and reradiated and its velocity
decreases.
39. Colors
of objects is the colors of lights spectrum it reflect
40. Black
object absorb all spectrum of light incident open it.
41. White
object reflect all spectrum of light incident open it.
42. Transparent
object transmit all colors of light
43. Translucent
object scatter all spectrum of visible light impinging on it.
44. When
light fall on an object some of it part of it is absorbed, transmitted or
reflected depending on the type of the object.
45. A
perfect body that absorbed all colors of light at all wavelength, all
temperature and all angle of incidence is called a blackbody.
46. Light
is the primary ingredient for photosynthesis
47. Bioluminescence
is the production and emission of light by living organisms.
48. The
emission of light during chemical reaction which does not produce sufficient
heat is called chemoluminescence.
49. The
transfer of light from one place to another without any intervening medium is
called radiation
50. The
study of properties and behavior of light is called optics
51. Ole
Roemer is the first scientist who significantly attempted to
measure the speed the light
52. The
speed of light in vacuum is 299 792 458 meters per second
53. The
speed of light in air ¾ of its speed in vacuum
54. Light
can be brought to a standstill when passed through the Bose-Einstein condensate
of rubidium.
55. Substance
emit radiation when they absorb light in a process called fluorescence
56. Refracting
index of materials increases with decreasing wavelength.
57. Violet
light bends more than red light when passing through a medium.
58. When
light is passed through a prism, violet deviate the most, red deviate the least
while the rest are in between.
59. Diffraction
is the bending of light around thin corners.
60. Interference
occurs when two light ray meet at a point, it could constructive or destructive
interference.
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