The Human Eye and the Colourful World — Class 10 Science PYQs

When you look at an object very close to your eyes, the :

Assertion (A) : When rays of white light pass through a prism, on emerging they give spectrum of seven colours.
Reason (R) : It is due to the scattering of light that red light bends minimum and violet light bends the maximum.

A person is unable to read a book placed closer than $1\mathrm{m}$ from his eyes. Identify the defect of vision in his eyes. Draw the ray diagrams to show the defect of vision and its correction.

An old person is suffering from an eye defect caused by weakening of ciliary muscles and diminishing flexibility of the eye lens. If the defect of vision is '$a$' which can be corrected by lens '$b$', then '$a$' and '$b$' respectively are :

The white light entering a glass prism, gets split into its constituent colours. It is observed that :

The phenomenon responsible for making the smoke particles visible when a beam of sunlight enters a smoke filled room through a narrow hole is :

In the given figure the angle of incidence and the angle of deviation respectively are :

A person allowed a narrow beam of white light from the sun to enter a dark room through a small aperture and placed a glass prism in its path in such a manner that the beam falls on the face AB of the prism as shown in the figure.
(a) Name the phenomenon due to which a prism splits the incident white light into a band of colours.
(b) State the reason of getting a band of seven colours in the above case.
(c) (i) Explain with the help of a labelled ray diagram, an experimental arrangement to show the recombination of the spectrum of white light.
OR
(c) (ii) Draw a labelled ray diagram to show the formation of a rainbow.

In the human eye, most of the refraction for the light rays entering the eye occurs at the surface of :

The part of the human eye which can modify the curvature of the eye lens to some extent is :