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प्रश्न
Explain the refraction of light through a triangular glass prism using a labelled ray diagram. Hence define the angle of deviation.
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उत्तर
Here PE is the incident ray, EF is the refracted ray and FS is the emergent ray. A ray of light is entering from air to glass at the first surface AB. The light ray on refraction has bent towards the normal. At the second surface AC, the light ray has entered from glass to air. Hence it has bent away from normal. The specific shape of the prism makes the emergent ray bend at an angle to the direction of the incident ray. This angle is called the angle of deviation. In this case ∠D is the angle of deviation. The angle between the incident ray and emergent ray is called angle of deviation.
PE = Incident Ray
EF = Refracted ray
FS = Emergent ray
∠A = Angle of the prism
∠i = Angle of incidence
∠r = Angle of refraction
∠e = Angle of emergence
∠D = Angle of deviation
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संबंधित प्रश्न
The correct sequencing of angle of incidence, angle of emergence, angle of refraction and lateral displacement shown in the following diagram by digits 1, 2, 3 and 4 is:
(a) 2, 4, 1, 3
(b) 2, 1, 4, 3
(c) 1, 2, 4, 3
(d) 2, 1, 3, 4
Name the phenomenon which causes the twinkling of stars.
Name two effects produced by the atmospheric refraction.
State whether the following statement is true or false:
The planets twinkle at night due to atmospheric refraction of light.
Fill in the following blank with suitable word:
We can see the sun about ................ minutes before the actual sunrise and about ................ minutes after the actual sunset because of atmospheric ................
Why do stars seem higher than they actually are? Illustrate your answer with the help of a diagram.
The atmospheric refraction of light causes the twinkling of:
(a) planets only
(b) stars only
(c) planets and stars
(d) stars and satellites
The stars appear higher in the sky than they actually are, due to:
(a) diffraction of light
(b) scattering of light
(c) refraction of light
(d) reflection of light
Due to atmospheric refraction of sunlight, the time from sunrise to sunset is lengthened by about:
(a) 6 minutes
(b) 2 minutes
(c) 4 minutes
(d) 5 minutes
State one effect produced by the scattering of light by the atmosphere.
Why does the sky appear blue on a clear day?
Which of the following is not caused by the atmospheric refraction of light?
(a) twinkling of stars at night
(b) sun appearing higher in the sky than it actually is
(c) sun becoming visible two minutes before actual sunrise
(d) sun appearing red at sunset
A star sometimes appears brighter and some other times fainter. What is this effect called? State the reason for this effect.
The stars appear higher from horizon than they actually are. Explain why it is so.
Explain why the planets do not twinkle but the stars twinkle.
The air layer of the atmosphere whose temperature is less than the hot layer behave as optically:
Assertion: Sky appears blue in the day time.
Reason: White light is composed of seven colours.
How does refraction take place in the atmosphere? Why do stars twinkle but not the planets?
