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?

1. 1, 2 and 3
2. 3, 4 and 5
3. 1, 2 and 4
4. 2, 3 and 5

Answer 1

Correct Answer - Option 3 : 1, 2 and 4

The correct answer is 1,2 and 4.

• Optical illusions are visual illusions that differ from reality.
• The size of the sun at dusk, the Color of the sun at dawn, and the Twinkle of stars in the sky are optical illusions because of atmospheric conditions.
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• Size of the sun at dusk: The size of the sun at different intervals of the day will appear different because of optical illusion. It will appear large during the morning time because we see it with other objects in the environment. It will appear smaller in noon time because of the presence of clear sky and appears more clear during evening time.
• Color of the Sun at dawn: The color of the sun resembles optical illusion throughout the day. Light is composed of many colors and out of all those colors, red color travels farthest in the atmosphere and appears to be seen at last. During noon time, Sun appears whitish and yellowish in color.
• The twinkle of stars in the sky: Stars have their own light and as a result cause an optical illusion. This happens when light travels through various layers of the atmosphere before reaching human eyes.

• Moon being visible at Dawn: It is not an optical illusion because the moon is visible at dawn during the half of the cycle of Full Moon to just before New Moon.
• Polestar being visible in the sky: It is not an optical illusion as Polestars appears in North or South pole which completely depends on earth rotation.