$(a)$ What is "power of accommodation of the eye"?
$(b)$ What happens to the image distance when the object being viewed is moved away from the eye?

Presbyopia is a type of far-sightedness.

Which lens is used to correct the defect of hypermetropia (farsightedness)?

Explain how a normal human eye is able to see distinctly objects placed at a distance as well as those placed at a nearer distance. What is the far point and near point of a normal human eye?

Which of the following is true for the eye defect known as hypermetropia (farsightedness)?

$A$ beam of white light falling on a glass prism gets split up into seven colours marked $1$ to $7$ as shown in the diagram.
$(a)$ The colours at positions marked $3$ and $5$ are similar to the colour of the sky and the colour of gold metal respectively. Is the above statement made by the student correct or incorrect? Justify.
$(b)$ Which of the above shown positions corresponds approximately to the colour of:
$(i)$ a brinjal
$(ii)$ danger signal
$(iii)$ neel (indigo) which is applied to clothes
$(iv)$ orange