Class 10 Science

Chapter 10 Solutions — The Human Eye and the Colourful World

Open Solutions PDF →Also seeTextbook page→

Open Solutions PDFReads in your browser→Also seeTextbook page→

Solutions

Overview

Step-by-step NCERT solutions for The Human Eye and the Colourful World (Chapter 10, CBSE Class 10 Science) — the full working for every question, not just the final answer. You can also read the The Human Eye and the Colourful World textbook chapter.

Solved

What these solutions cover

All 28 questions in The Human Eye and the Colourful World are solved in the PDF. Here's what's inside, exercise by exercise:

The Human Eye

What is meant by power of accommodation of the eye?
A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?
What is the far point and near point of the human eye with normal vision?
A student has difficulty reading the blackboard while sitting in the last row. What could be the defect of vision? How can it be corrected?

Refraction through a Prism

The human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This is due to
The human eye forms the image of an object at its
The least distance of distinct vision for a young adult with normal vision is about

Dispersion of Light and Atmospheric Phenomena

What is the angle of deviation?
What is dispersion of white light by a glass prism?
Why do we see a rainbow in the sky only after rainfall?

Atmospheric Refraction and Scattering

Why is the colour of the clear sky blue?
Why does the Sun appear reddish early in the morning?
Why does the sky appear dark instead of blue to an astronaut?

End-of-Chapter Exercise

1.
The human eye can focus objects at different distances by adjusting the focal length of the eye lens. This is due to
- (a) presbyopia
- (b) accommodation
- (c) near-sightedness
- (d) far-sightedness
2.
The human eye forms the image of an object at its
- (a) cornea
- (b) iris
- (c) pupil
- (d) retina
3.
The least distance of distinct vision for a young adult with normal vision is about
- (a) 25 m
- (b) 2.5 cm
- (c) 25 cm
- (d) 2.5 m
4.
When light rays enter the eye, most of the refraction occurs at the
- (a) crystalline lens
- (b) outer surface of the cornea
- (c) iris
- (d) pupil
5.
The change in focal length of an eye lens is caused by the action of the
- (a) pupil
- (b) retina
- (c) ciliary muscles
- (d) iris
6.
The eye can focus on objects at different distances by changing the
- (a) focal length of the eye lens
- (b) distance between the eye lens and the retina
- (c) shape of the eyeball
- (d) none of the above
7.
A person needs a lens of power -5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting
- (i) distant vision, and
- (ii) near vision?
The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.
Why is a normal eye not able to see clearly the objects placed closer than 25 cm?
What happens to the image distance in the eye when we increase the distance of an object from the eye?
Why do stars twinkle?
Explain why the planets do not twinkle.
Why does the Sun appear reddish early in the morning?
Why does the sky appear dark instead of blue to an astronaut?

Keep solving