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A small piece of wood is floating on the...

A small piece of wood is floating on the surface of a 2.5 m deep lake. Where does the shadow form on the bottom when the sun is just setting? Refractive index of water = 4/3

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The correct Answer is:
B, C, D
Height of the lake =2.5 m
When the sun is just setting q is approximately =900
`:. (sini)/(sinr)=mu_2/mu_1`
`rarr 1/(sinr)=(4/3)/1`
`rarr sinr=3/4 rarr r=49^@`
Thus (x/2.5)=tanr=1.15`
`rarr x=2.5xx1.15=2.8m`
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HC VERMA-GEOMETRICAL OPTICS-Exercises
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  13. An optical fibre (mu = 1.72) is surrounded by a glass coating (mu= 1.5...

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  14. A light ray is incident normally on the face AB of a right-angled pris...

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  15. Find the maximum angle of refraction when a light ray is refracted fro...

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  16. Light is incident from glass (mu=1.5) to air. Sketch thevariation of t...

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  17. Light is incident from glass (mu = 1.50) to water (mu = 1.33) find th...

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  18. Light falls from glass (mu=1.5) to air. Find the angle of incidence fo...

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  19. A point source is placed at a depth h below the surface of water (refr...

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