1. _____ is a form of energy which travels in the form of waves
2. The path of light is called ____
3. Group of rays are called as_____
4. Any object which gives out light are termed as _____
5. Some of the sources emit their own light and they are called as____
6. All the stars, including the Sun, are examples for _______
7. Light always travels along a ______” line
8.The speed of light in vacuum or air is____
9. Different coloured light has ______ wavelength and frequency
10. ____light has the lowest wavelength
11._____light has the highest wavelength.
12. When a ray of light travels from one transparent medium into another obliquely,
the path of the light undergoes
13._______takes place due to the difference in the velocity of light in different media
14. The velocity of light is____ in a
15. The velocity of light is____ in a denser medium
16. The incident ray, the refracted ray of light and the normal to the refracting surface all lie in the ____ plane.
17. Second law of refraction is also known as ______
18. When light travels from a denser medium into a rarer medium, the refracted ray is _____away from the normal drawn to the interface.
19. If a source of light produces a light of single colour, it is known as _____
20. When a beam of white light or composite light is refracted through any transparent media such as glass or water, it is split into its component colours. This phenomenon is called as
21. The band of colours is termed as____
22. Angle of refraction is the smallest for ___
23. Angle of refraction is the highest for
24. The interacting particle of the medium is called as_____
25. The refractive index of a medium is dependent on the _______of the light.
26. When sunlight enters the Earth’s atmosphere, the atoms and molecules of different gases present in the atmosphere refract the light in all possible directions. This is called as____
27. The interacting particle of the medium is called as_____
28. If the energy of the incident beam of light and the scattered beam of light are same, then it is called as
29. If the energy of the incident beam of light and the scattered beam of light are not same, then it is called as____
30. The scattering of sunlight by the atoms or molecules of the gases in the earth’s atmosphere is known as _______
31.____scattering takes place when the diameter of the scatterer is similar to or larger than the wavelength of the incident light.
32. _______ is caused by pollen, dust, smoke, water droplets, and other particles in
the lower portion of the atmosphere.
33.______ is responsible for the white appearance of the clouds.
34. The scattering of light rays by the colloidal particles in the colloidal solution is
35. _______Scattering is defined as “The interaction of light ray with the particles of pure liquids or transparent solids, which leads to a change in wavelength or frequency.”
36. The spectral lines having frequency equal to the incident ray frequency is called _____
37. The spectral lines which are having frequencies other than the incident ray
frequency are called
38. A _______is an optically transparent medium bounded by two spherical refracting surfaces or one plane and one spherical surface
39. Convex lens is also called as
40. Concave lens is also called as
41. If one of the faces of a bi-convex lens is plane, it is known as a_____
42. If one of the faces of a bi-concave lens is plane, it is known as a ______
43. When an object is placed in front of a lens, the ______from the object fall on the lens
44. ________lenses are used as camera lenses
45. ________are used as magnifying lenses
46. ________are used in making microscope, telescope and slide projectors
47. Convex lensrs are used to correct the defect of vision called
48. Concave lenses are used as eye lens of _______
49. ________are used in wide angle spy hole in doors.
50. ____ are used to correct the defect of vision called ‘myopia
51. All lenses are made up of ________materials
52. When a ray of light falls on a lens, the ability to converge or diverge these light rays depends on the _____of the lens.
53. The ability of a lens to converge (convex lens) or diverge (concave lens) is called as its____
54. The SI unit of power of a lens is ____
55. The power of a ____lens is taken as positive
56. The power of a____ lens is taken, as negative.
57._____is a converging lens.
58. _____ is a diverging lens
59. The eye ball is approximately spherical in shape with a diameter of about ____
60. _____protects the internal parts of the eye
61.____ is the thin and transparent layer on the front surface of the eyeball
62. ____ is the coloured part of the eye
63. ______controls amount of light entering into the
pupil like camera aperture.
64.____is the centre part of the Iris. It is the pathway for the light to retina.
65. ______is the back surface of the eye. It is the most sensitive part of human eye, on which real and inverted image of objects is formed.
66. Eye lens is fixed between the______
67. _____ is made of a flexible, jelly-like material
68. The minimum distance required to see the objects distinctly without strain is called ____distance of distinct vision
69. A normal human eye can clearly see all the objects placed between _____ and infinity
70. _____ also known as short sightedness
71. ______, also known as long sightedness, occurs due to the shortening of
72. Some persons may have both the defects of vision – myopia as well as hypermetropia. This can be corrected by
73. In this defect, eye cannot see parallel and horizontal lines clearly
74. Simple microscope has a convex lens of short_____
75. _____ are used by watch repairers and jewellers.
76. _____is used to observe finger prints in the field of
77. A ______ microscope consists of two
78. A _______ microscope is one of the best instrument for measuring very small length with high degree of accuracy at the order of 0.01mm.
79. ______works based on the principle of vernier. Its least count is 0.01 mm
80. _______is an optical instrument to see
the distant objects
81.The first telescope was invented by _____ in 1608
82. ______ is used to view heavenly bodies like stars, planets galaxies and satellites.