NCERT Exemplar Class 10 Science Chapter 11 Human Eye And Colourful World

Chapter 11 Human Eye And Colorful World NCERT Exemplar for class 10 Science

NCERT Exemplar Solutions for Class 10 Science Chapter 11 Human Eye and Colourful World include the solutions to all the questions present in the NCERT Class 10 Exemplar textbook. These NCERT Exemplar Solutions are created in a systematic manner according to the latest CBSE pattern. Chapter 11 is all about studying the structure of the human eye and other concepts like the power of accommodation, atmospheric refraction, etc. Students will study some of the optical phenomena occurring in nature, the rainbow formation, and splitting of white light and blue color of the sky.

While the chapter can sometimes be hard to grasp, the free NCERT Exemplar solutions for Chapter 11 for students in having better clarity about the different kinds of questions in the chapter. The exemplars available here are free to download in PDF and will help students to solve the questions quickly and find answers to all the important questions asked in the board exam from this chapter. They can use these NCERT Exemplar Solutions to study and to achieve better results in the class tests and the CBSE Board exams.

Have a look at Class 10 Science Chapter 11 NCERT Exemplar Solutions below.

1. A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power

(a) + 0.5 D

(b) – 0.5 D

(c) + 0.2 D

(d) – 0.2 D

Soln:

The answer is (b) – 0.5 D

Explanation:

The person is Myopic, and he needs a concave mirror hence the power would be in negative.

P=1/f=1/2m= 0.5 D

2. A student sitting on the last bench can read the letters written on the blackboard but is not able to read the letters written in his textbook. Which of the following statements is correct?

(a) The near point of his eyes has receded away

(b) The near point of his eyes has come closer to him

(c) The far point of his eyes has come closer to him

(d) The far point of his eyes has receded away

Soln:

Answer is (a) The near point of his eyes has receded away

Explanation:

Near point of eye moves away for 25 cm in hypermetropia. Hence the person should keep the book 25 cm apart to read properly.

3. A prism ABC (with BC as a base) is placed in different orientations. A narrow beam of white light is incident on the prism as shown in Figure 11.1. In which of the following cases, after dispersion, the third colour from the top corresponds to the colour of the sky? The Human Eye and the Colourful World CHAPTER11 Fig.11.1

(a) (i)

(b) (ii)

(c) (iii)

(d) (iv)

Soln:

The answer is (b) (ii)

Explanation:

Band of colour show violet at the bottom if the prism is kept with BC in the bottom. if the prism is kept with BC in the top, then violet will be in the top followed by indigo and blue.

4. At noon the sun appears white as

(a) light is least scattered

(b) all the colours of the white light are scattered away

(c) blue colour is scattered the most

(d) red colour is scattered the most

Soln:

The answer is (b) all the colours of the white light are scattered away

Explanation:

This is due to the dispersion of light by the atmosphere.

5. Which of the following phenomena of light are involved in the formation of a rainbow?

(a) Reflection, refraction and dispersion

(b) Refraction, dispersion and total internal reflection

(c) Refraction, dispersion and internal reflection

(d) Dispersion, scattering and total internal reflection

Soln:

Answer is (c) Refraction, dispersion and internal reflection

Explanation:

Dispersion of light leads to scattering of white light into different colour to an angle to cause internal reflection.rs. Refraction bends incident light leading to the formation of rainbow.

6. Twinkling of stars is due to atmospheric

(a) dispersion of light by water droplets

(b) refraction of light by different layers of varying refractive indices

(c) scattering of light by dust particles

(d) internal reflection of light by clouds

Soln:

The answer is (b) refraction of light by different layers of varying refractive indices

Explanation:

Refraction of light keeps the position of the source of light change. This will make the stars sparkle.

7. The clear sky appears blue because

(a) blue light gets absorbed in the atmosphere

(b) ultraviolet radiations are absorbed in the atmosphere

(c) violet and blue lights get scattered more than lights of all other colours by the atmosphere

(d) light of all other colours is scattered more than the violet and blue colour lights by the atmosphere

Soln:

Answer is (c) violet and blue lights get scattered more than lights of all other colours by the atmosphere.

8. Which of the following statements is correct regarding the propagation of light of different colours of white light in air?

(a) Red light moves fastest

(b) Blue light moves faster than green light

(c) All the colours of the white light move with the same speed

(d) Yellow light moves with the mean speed as that of the red and the violet light

Soln:

Answer is (c) All the colours of the white light move with the same speed

9. The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light

(a) is scattered the most by smoke or fog

(b) is scattered the least by smoke or fog

(c) is absorbed the most by smoke or fog

(d) moves fastest in air

Soln:

The answer is (b) is scattered the least by smoke or fog

10. Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?

(a) Dispersion of light

(b) Scattering of light

(c) Total internal reflection of light

(d) Reflection of light from the earth

Soln:

The answer is (b) Scattering of light

Explanation:

Because red colour scatters the least, it travels a long distance. During sunset or sunrise, light has to travel a long distance to reach the earth. Hence light will be red when it reaches us.

11. The bluish colour of water in the deep sea is due to

(a) the presence of algae and other plants found in water

(b) reflection of sky in water

(c) scattering of light

(d) absorption of light by the sea

Soln:

The answer is (b) reflection of sky in water

Explanation:

Water is colourless water attains the colour it is reflected by. Hence sea appears blue.

12. 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

Soln:

The answer is (b) the outer surface of the cornea

Explanation:

The cornea is a thin membrane through which light is entered. The incident light rays are bent due to cornea and are converged, which results in image formation at the retina. So, most of the refraction occurs at the iris of the eye.

13. The focal length of the eye lens increases when eye muscles

(a) are relaxed and the lens becomes thinner

(b) contract and lens become thicker

(c) are relaxed and the lens becomes thicker

(d) contract and lens becomes thinner

Soln:

Answer is (a) are relaxed and the lens becomes thinner

14. Which of the following statement is correct?

(a) A person with myopia can see distant objects clearly

(b) A person with hypermetropia can see nearby objects clearly

(c) A person with myopia can see nearby objects clearly

(d) A person with hypermetropia cannot see distant objects clearly

Soln:

Answer is (c) A person with myopia can see nearby objects clearly

Explanation:

Myopia is a condition where a person cannot see the distant objects clearly and he can see nearer objects clearly.

Hypermetropia is a condition in which a person cannot see the nearer object clearly but he can see the distant objects clearly.