In which direction is a rainbow formed during the morning hours in the rainy season?

Which colour has the maximum wavelength and which has the minimum wavelength? Explain on the basis of wavelength which colour bends the most and which colour bends the least.

$A$ student cannot read properly from the blackboard while sitting on the front desk in a large classroom. However,he can read clearly while sitting on the last desk of the classroom.
$(a)$ Draw ray diagrams to illustrate the formation of the image of the blackboard writing by his eye lens when he is seated at the $(i)$ front desk,$(ii)$ last desk.
$(b)$ Name the defect of the eye from which the student is suffering.
$(c)$ Name the type of lens that would enable him to see the blackboard writing clearly when seated at the front desk. Draw a ray diagram to illustrate how this lens helps him to see clearly.

Give one cause of near-sightedness (myopia).

$A$ person cannot see objects distinctly when placed beyond $2\, m$.
$(a)$ Identify the eye defect.
$(b)$ Give two reasons for this defect.
$(c)$ Calculate the power and nature of the lens he should be using to see the distant objects clearly.
$(d)$ Draw the ray diagrams for the defective and the corrected eye.

Why does the sky appear dark to passengers flying at high altitudes?