Consider the following phenomena:1. Size of the sun at dusk 2. Colour of the sun at dawn 3. Moon being visible at dawn 4. Twinkle of stars in the sky 5. Polestar being visible in the sky Which of the above are optical illusions?

Question

Consider the following phenomena:1. Size of the sun at dusk 2. Colour of the sun at dawn 3. Moon being visible at dawn 4. Twinkle of stars in the sky 5. Polestar being visible in the sky Which of the above are optical illusions?

Quintessence Classes · Accepted Answer

The correct answer is 1, 2 and 4 only. • Correct Answer: (a) 1, 2 and 4 only• Explanation: These are caused by atmospheric refraction and scattering. The Moon and Polestar (3 and 5) are physically present in the sky, not illusions created by the atmosphere.

Answer

3, 4 and 5 only

Answer

1, 2 and 5 only

Answer

2, 3 and 5 only

Consider the following phenomena:

1. Size of the sun at dusk
2. Colour of the sun at dawn
3. Moon being visible at dawn
4. Twinkle of stars in the sky
5. Polestar being visible in the sky

Which of the above are optical illusions?

Answer & Explanation

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UPSC CSE 2013 Prelims

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