Tag: some natural phenomena of light
Questions Related to some natural phenomena of light
Blue colour of wter in sea is due to
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refraction of blue light by impurities
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refraction blue sky by water
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scattering of light by water
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None of the above
The colour of a colloidal solution depends on the wavelength of the light scattered by the dispersed particles, which in turn depends on the size and the nature of particle.
The colour of water in sea is blue on the scattering of light by water.
By which optical phenomena the splitting of white light into seven constituent colours occur?
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Refraction
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Dispersion
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Reflection
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Interference
Dispersion optical phenomena the splitting of white light into seven constituent colors occur. These colors are often observed as light passes through a triangular prism. Upon passage through the prism, the white light is separated into its component colors - red, orange, yellow, green, blue and violet. The separation of visible light into its different colors is known as dispersion. It was mentioned in the ight and color unit that each color is characteristic of a distinct wave frequency and different frequencies of light waves will bend varying amounts upon passage through a prism.
Intensity of light ray in a direction after scattering by small particles (smaller than wavelength):
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decreases.
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remains the same.
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increases.
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may increase or decrease depending on the medium in the corresponding direction.
After scattering of light by small particles, it spreads in all directions. Hence, the intensity of the scattered light in a direction is smaller then the intensity of the incident light wave.
Which of the following observations cannot be explained by Tyndall Effect?
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Sunlight entering a smoke filled dark room from a tiny hole.
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Sunlight entering from a canopy of dense forest.
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Speed of light in vacuum is $3 \times 10^8\ m/s$
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Light passed through a milk solution.
Tyndall Effect is observed in many natural phenomenon. It involves the scattering of light in a colloidal solution by fine particles. Some common phenomenon include the sunlight entering through forest canopy, sunlight entering a dark room from a small hole and light passed through a milk solution. Speed of light in a medium is defined by the refractive index of the medium. It is maximum for vacuum and is given by the value $3 \times 10^8\ m/s$.
Tyndall effect is shown by:
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particles in colloidal solution.
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particles in a very fine suspension
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large particles like stones.
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both A and B
The Tyndall Effect (Tyndall scattering), is light scattering by particles in a colloid or else particles in a very fine suspension. It is observed in aerosol, iris, milk, etc.
Which of the following phenomenon is involved in Tyndall effect?
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Reflection of light.
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Refraction of light.
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Scattering of light.
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Magnification of light.
The Tyndall Effect (Tyndall scattering), is light scattering by particles in a colloid or else particles in a very fine suspension. The amount of scattering is inversely proportional to the fourth power of wavelength and hence the colour of the colloidal solution is the same as the least coloured wavelength.
Which of the following quantities changes during the process of scattering?
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Speed.
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Wavelength.
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Direction of propagation.
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None of the above.
After scattering, light is spread in all directions and hence the direction of propagation changes. Wavelength, speed and frequency of the light remains unchanged during the process. Also, the intensity of the light ray in a direction changes.
Which of the following occurs in scattering?
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Light is reflected back in the original direction.
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Light is split into its spectrum.
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Photons in the light wave are absorbed by the particles.
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Absorption and re-emission of light energy by small particles.
Scattering is the process of absorption and then re-emission of light energy by particles smaller than the wavelength of the incident light ray.
After scattering, the light moves in:
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the same direction as the original light ray.
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opposite to the original direction of the light ray.
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all directions.
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the direction of the shortest path.
In scattering, light wave is absorbed and re-emitted in all directions without a change in the wavelength of the light ray.
Stars twinkle but planets do not twinkle because
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Stars emit their own light but planets receive light from the stars
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Stars do not from a part of solar system
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Stars from a point source of light while planets are considered as a collection of a large number of point sources of light
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During refraction of star light from the atmosphere, star light bends more towards the normal as compared to the planets
Light of the star is bent many times and in random directions as light is bent when it hits a change in density. This random refraction results in the star winking out - twinkling.