The Human Eye and the Colourful world

# Class 10 Science Chapter 10 The Human Eye and the Colourful World Important Questions

Here are some critical Chapter 10 The Human Eye and the Colourful world Problems for Class 10 Science. These inquiries are intended to aid students in studying for and performing well on the CBSE Class 10 Science Examination 2023–24. Students can clear up their concerns and be ready for the exams by practising different types of questions. By answering these questions, you'll increase your confidence while also sharpening your problem-solving abilities

## Introduction

In Chapter 10 The Human Eye and the Colourful World you will study about The Human Eye, Defects of Vision and their Correction,Refraction of Light through a Prism, Dispersion of White Light by a Glass Prism, Atmospheric Refraction and Scattering of Light.

### Class 10 The Human Eye and the Colourful World Important Questions and Answers

#### (a) The emergent ray is parallel to the incident ray(b) The emergent ray bends at an angle to the direction of the incident ray.(c) The emergent ray and the refracted ray are at right angles to each other.(d) The emergent ray is perpendicular to the incident ray.

Ans. (b)

Explanation:
When a ray of light passes through a prism and undergoes refraction, the emergent ray takes a different path compared to the incident ray. The emergent ray bends at an angle to the direction of the incident ray.

#### (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

Ans. (a)

Explanation:
At noon because the sun is overhead, the light is scattered the least and hence appears white. When it is overhead, it has less air to travel through and the scattering from dust and other particles is reduced if the distance to be travelled in air is reduced.

#### Q3. John has undergone all medication including wearing spectacles, lens and laser treatment. None of the treatment helped him to recover his eyesight. What would be your suggestion to overcome his problem in his eyesight?

Explanation:
Though all the treatment for recovering from his eye problems did not help him out, I would suggest he opt for eye transplantation which would get his eyesight back to normal. In transplantation of the eye, the entire diseased eye cannot be replaced. Only the diseased cornea can be replaced by the donated cornea.

#### Q4. Why do clouds appear white? Explain.

Explanation:
The clouds contain dust particles and water molecules of size bigger than the wavelength of visible light, so they scatter all colours of incident white light from the sun to the same extent and hence when the scattered light reaches our eyes, the clouds are seen white.

#### Q5. Differentiate between presbyopia and cataract.

Explanation:

S no. Presbyopia Cataract
1. It is a defect of vision due to which an old person cannot see the nearby objects clearly due to loss of power of accommodation of eye. It is the medical condition in which the lens of the eye of a person becomes progressively cloudy resulting in blurred vision.
2. It can be corrected by using spectacles having bifocal lens of suitable power. It cannot be corrected by any type of spectacle lenses.
3. Surgical operations is not required to rectify Presbyopia. The vision of a person can be restored by getting surgery done on the eye having cataract.

#### CBSE Class 10 Science Chapter wise Important Questions

Chapter No. Chapter Name
Chapter 1 Chemical Reactions and Equations
Chapter 2 Acid, Bases and Salts
Chapter 3 Metals and Non-Metals
Chapter 4 Carbon and its Compounds
Chapter 5 Life Processes
Chapter 6 Control and Coordination
Chapter 7 How do Organisms Reproduce
Chapter 8 Heredity
Chapter 9 Light : Reflection and Refraction
Chapter 10 The Human Eye and the Colourful world
Chapter 11 Electricity
Chapter 12 Magnetic Effects of Electric Current
Chapter 13 Our Environment

#### Conclusion

oswal.io offers a thorough set of questions for learning the topic in a better way if you're looking to further practise and improve your grasp of the concepts covered in the chapter.

#### Q1 : Why does the Sun appear reddish early in the morning?

Ans: White light coming from the sun has to travel more distance in the atmosphere before reaching the observer. During this, the scattering of all coloured lights except the light corresponding to red colour takes place and so, only the red coloured light reaches the observer. Therefore, the sun appears reddish at sunrise and sunset.

#### Q2: Why is a normal eye not able to see clearly the objects placed closer than 25 cm?

Ans:  A normal eye is not able to see the objects placed closer than 25 cm clearly because the ciliary muscles of the eyes are unable to contract beyond a certain limit.

#### Q3 : Why do stars twinkle?

Ans: The twinkling of a star is due to atmospheric refraction of starlight. The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth. The atmospheric refraction occurs in a medium of gradually changing refractive index.

#### Q4 : What happens to the image distance in the eye when we increase the distance of an object from the eye?

Ans: The image is formed on the retina even on increasing the distance of an object from the eye. The eye lens becomes thinner and its focal length increases as the object is moved away from the eye.

#### Q5 : Explain why the planets do not twinkle.

Ans: Unlike stars, planets don’t twinkle. Stars are so distant that they appear as pinpoints of light in the night sky, even when viewed through a telescope. Since all the light is coming from a single point, its path is highly susceptible to atmospheric interference (i.e. their light is easily diffracted).

## Chapter Wise  Important Questions for CBSE Board Class 10 Science

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