Why does the sun appear reddish early in the morning? Will this phenomenon be observed by an observer on the moon? Justify your answer with a reason.
OR
Why does sun appear reddish at sunrise? Give reason.

Five persons A, B, C, D and E have diabetes, leukaemia, asthma, meningitis and hepatitis, respectively.

1. Which of these persons can donate eyes?
2. Which of these persons cannot donate eyes?

Explain why the planets do not twinkle but the stars twinkle.

No rainbow could be observed from the surface of Moon by the astronauts. What could be the possible reason?

Explain why, if we look at objects through the hot air over a fire, the objects appear to be moving (or shaking) slightly.

Water in deep sea is blue in colour. Why?

What are rods and cones in the retina of an? Why is our night vision relatively poor compared to the night vision of an owl?

Explain why, the sun can be seen about two minutes before actual sunrise. Draw a diagram to illustrate your answer?

Why do stars seem higher than they actually are? Illustrate your answer with the help of a diagram.

Name the atmospheric phenomenon due to which the sun can be seen above the horizon about two minutes before actual sunrise.