Physics
Grade-10
Easy
Question
The stars appear to twinkle from the Earth’s surface. This is due to ____.
- Reflection of light
- Dispersion of light
- Atmospheric refraction of light
- Internal reflection of light
Hint:
This is due to. frequent absorption of star light by earth's atmosphere.
The correct answer is: Atmospheric refraction of light
The twinkling of a star is due to atmospheric refraction of starlight.
∙ The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth.
∙ The atmospheric refraction occurs in a medium of gradually changing refractive index.
∙ The apparent position of the star is not stationary but keeps on changing slightly, since the physical conditions of the earth’s atmosphere are not stationary.
∙ As the path of rays of light coming from the star goes on varying slightly, the apparent position of the star fluctuates and the amount of starlight entering the eye flickers – the star sometimes appears brighter, and at some other time, fainter, which is the twinkling effect.
Related Questions to study
Physics
Stars can be considered as _____ sources of light.
- Point-sized
- Extended
- Yellow
- None of the above
Stars can be considered as _____ sources of light.
PhysicsGrade-10
- Point-sized
- Extended
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As the wavelength of the incident light increases, the deviation in its path on getting refracted through a prism ____.
- Increases
- Decreases
- Stays the same
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As the wavelength of the incident light increases, the deviation in its path on getting refracted through a prism ____.
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- Increases
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In which of the following light wavelengths is the lowest deviation observed when it gets refracted through a prism?
- 700 nm
- 245 nm
- 483 nm
- 567 nm
In which of the following light wavelengths is the lowest deviation observed when it gets refracted through a prism?
PhysicsGrade-10
- 700 nm
- 245 nm
- 483 nm
- 567 nm
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In which of the following light wavelengths is the highest deviation observed when it gets refracted through a prism?
- 700 nm
- 245 nm
- 483 nm
- 567 nm
In which of the following light wavelengths is the highest deviation observed when it gets refracted through a prism?
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- 700 nm
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Which of these lights would deviate highest from its path?
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Which of these lights would deviate highest from its path?
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When light gets refracted through a triangular prism, the angle of incidence is _____ the angle of refraction.
- Always equal
- May not be equal
- Sometimes equal
- None of the above
When light gets refracted through a triangular prism, the angle of incidence is _____ the angle of refraction.
PhysicsGrade-10
- Always equal
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When a light ray gets refracted through a glass slab, the incident ray is ____.
- Parallel to the emergent ray
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When a light ray gets refracted through a glass slab, the incident ray is ____.
PhysicsGrade-10
- Parallel to the emergent ray
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When a light ray refracts through a triangular prism, it diverts its path through an angle of _____.
- Incidence
- Dispersion
- Deviation
- Propagation
When a light ray refracts through a triangular prism, it diverts its path through an angle of _____.
PhysicsGrade-10
- Incidence
- Dispersion
- Deviation
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When a light ray refracts through a glass slab, the incident ray is ____ to the emergent ray.
- Parallel
- Perpendicular
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When a light ray refracts through a glass slab, the incident ray is ____ to the emergent ray.
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_____ is a measure of amount of deviation of the incident ray from its usual path.
- Angle of dispersion
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_____ is a measure of amount of deviation of the incident ray from its usual path.
PhysicsGrade-10
- Angle of dispersion
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Red colored light bends ____ when passed through a prism, as compared to other colors.
- The most
- The least
- Moderately
- Does not bend
Red colored light bends ____ when passed through a prism, as compared to other colors.
PhysicsGrade-10
- The most
- The least
- Moderately
- Does not bend
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When the refractive index of the prism is increased, the angle of deviation _____.
- Decreases
- Increases
- Stays the same
- Becomes zero
When the refractive index of the prism is increased, the angle of deviation _____.
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- Decreases
- Increases
- Stays the same
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When the refractive index of the surrounding medium is decreased, the angle of deviation _____.
- Decreases
- Increases
- Stays the same
- Becomes zero
When the refractive index of the surrounding medium is decreased, the angle of deviation _____.
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- Decreases
- Increases
- Stays the same
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Violet colored light bends ____ when passed through a prism, as compared to other colors.
- The most
- The least
- Moderately
- Does not bend
Violet colored light bends ____ when passed through a prism, as compared to other colors.
PhysicsGrade-10
- The most
- The least
- Moderately
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When a light ray refracts through a prism the incident ray is _____ to the emergent ray.
- Parallel
- Perpendicular
- Not parallel
- Coincident
When a light ray refracts through a prism the incident ray is _____ to the emergent ray.
PhysicsGrade-10
- Parallel
- Perpendicular
- Not parallel
- Coincident
