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प्रश्न
Explain: ‘How is a rainbow formed’?
उत्तर
1. The beautiful phenomenon of the rainbow is a combination of different phenomena – dispersion, refraction, and reflection of light.
2. The rainbow appears in the sky after a rain shower.
3. The water droplets act as small prisms.
4. When sunlight enters the water droplets present in the atmosphere, they refract and disperse the incident sunlight.
5. Then they reflect it internally inside the droplet and finally again refract it.
6. As a collective effect of all these phenomena, the seven-colored rainbows are observed.
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| Case study: Mirage in deserts |
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To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object. Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts. Based on the above facts, answer the following question: |
Which of the following phenomena is prominently involved in the formation of mirage in deserts?
| Case study: Mirage in deserts |
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A diamond is immersed in such a liquid which has its refractive index with respect to air as greater than the refractive index of water with respect to air. Then the critical angle of diamond-liquid interface as compared to critical angle of diamond-water interface will
| Case study: Mirage in deserts |
|
|
To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object. Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts. Based on the above facts, answer the following question: |
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