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On a hot summer night, the refractive in...

On a hot summer night, the refractive index of air is smallest near the ground and increases with height from the ground. When a light beam is directed horizontally, the Huygens. principle leads us to conclude that as it travels, the light beam 1......

A

becomes narrower

B

goes horizontally without any deflection

C

bends downwards

D

bends upwards

Text Solution

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The correct Answer is:
A, B, D

Assume a planar wavefront moving in horizontal direction. Its different parts will move with different speeds during its motion. Speed in rarer medium will be more and that in denser medium will be less hence its shape will be as shown.
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KUMAR PRAKASHAN-RAY OPTICS AND OPTICAL INSTRUMENTS-SECTION-D (MULTIPLE CHOICE QUESTIONS (MCQs))(MCQs ASKED IN COMPETITIVE EXAMS)
  1. A green light is incident from the water to the air-water interface at...

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  2. Monochromatic light is incident on a glass prism of angle A. If the re...

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  3. On a hot summer night, the refractive index of air is smallest near th...

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  4. An observer looks at a distant tree of height 10 m with a telescope of...

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  5. A diverging lens with magnitude of focal length 25 cm is placed at a d...

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  6. The eye can be regarded as a single refracting surface. The radius of ...

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  7. A thin lens made of glass (refractive index = 1.5) of focal length f= ...

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  8. If we need a magnification of 375 from a compound microscope of tube l...

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  9. A telescope has a magnification equal to 5 and the length of its tube ...

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  10. A plano-convex lens of radius of curvature 30 cm and refractive index ...

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  11. If nij is reftactive index of medium i with respect to medium j n21 X ...

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  12. Magnification of microscope of objective of focal length 5 mm is 400. ...

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  13. Refractive index of a prism is root2. One side of prism is polished, i...

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  14. Focal length of convex lens having refractive index 1.5 is 2 cm. If th...

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  15. Minimum deviation of prism having refractive index mu and small angle ...

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  16. For ...... light, focal length of convex lens is maximum.

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  17. Point source of light is placed 4 m below water surface in the medium ...

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  18. A lens is placed between a source of light and a wall . It forms image...

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  19. Light passes through a glass slab of refractive index .n. and thicknes...

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  20. An object is there on a wall. Now by help of convex lens, an image of ...

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