The Human Eye and The Colorful world Class 10th Notes- Free NCERT Class 10 Science Chapter 11 Notes - Download PDF

CBSE Class 10 Science Chapter 11 The Human Eye and the Colourful World Notes- Download Free PDF

The Human Eye And Colourful World class 10 notes, is a critical topic for not only passing board exams but also laying a solid foundation for advanced studies in Classes 11 and 12. This chapter of CBSE NCERT Science Book Class 10 explains the intricate mechanisms of the human eye and delves into the fascinating world of light and colour. Mastery of these concepts is more than just getting good grades; it serves as the foundation for many scientific disciplines.

Expertly curated notes on this chapter are invaluable resources for students. These class 10 maths chapter 11 notes, created by subject matter experts, cover all of the essential concepts, theories, and practical applications. They provide equitable learning opportunities for all students, regardless of background or financial constraints, and are free to access. By utilising these Human Eye And Colourful World notes Class 10, students can not only excel in their Class 10 exams but also prepare for the challenges of higher education. With clear explanations and illustrative examples, these notes help students navigate the complexities of optics and light, fostering a deeper understanding and appreciation for the subject.

** According to the CBSE Syllabus 2023-24, this chapter has been renumbered as Chapter 10.

Also, students can refer,

• NCERT Notes Class 10 Science
• NCERT Solutions for Class 10 Science Chapter 11 Human Eye and Colourful World
• NCERT Exemplar Class 10 Science chapter 11 Human Eye and Colourful World

NCERT Class 10 Physics Chapter 11 Notes

• Human Eye
• It is one of the most sensitive sense organs that is present in living organisms
• The image is formed on a screen that is light sensitive known as Retina.
• A thin membrane in the eye through which light enters the eye is known as Cornea.
• Eyeballs are spherical.
• The presence of the lens helps in adjusting objects at different distances on the retina.
• The dark muscular structure which controls the size of the pupil is Iris. Hence, the pupil regulates the amount of light entering the eye.
• Real, inverted images are formed on the retina. It contains light-sensitive cells Rods and Cons. These cells send signals to the brain with the help of the optic nerve

Power of Accommodation

The focal lens of the lens in the eye can be decreased or increased. The eye lens gets thin when muscles are relaxed. This results in increased focal length. It helps to see distant objects. And when the eye lens becomes thick, the focal length is decreased and we see nearby objects.

Power of accommodation is the ability of the eye lens to adjust the focal length.

• The near Point of the Eye is at 25 cm and the Far Point of the Eye is infinity.

• In old age, the lens becomes milky and cloudy, this is Cataract. This leads to complete or partial loss of vision.

Defects of the Vision and their Correction

The three common defects of vision :

Myopia ( Nearsightedness): In this distant objects cannot be seen clearly but nearby objects are visible.

Light from a far object forms an image before it reaches the retina

Corrected using concave lens

Correction of Myopia

• Hypermetropia ( Far-sightedness.) Nearby objects are seen clearly whereas distant objects can not be seen clearly.

• Image of a nearby object is formed behind the retina.

• Corrected using convex lens

Correction of Hypermetropia

• Presbyopia is, in which the power of accommodation decreases with ageing. They have difficulty in near vision as well as far vision. Bifocal lenses are used to correct the defects.

Dispersion of White Light in A Prism

When light falls on the prism, the prism splits the incident light into a band of seven colours. The colours observed are VIBGYOR (Violet, Indigo, Blue, Green, Yellow, Orange and Red). The band of colour is Spectrum. Thus, splitting of incident light into different colours is Dispersion. The splitting is because of the bending of light rays at different angles. Violet light bends the most whereas red light bends the least.

Recombination of spectrum of white light-

1 more prism is placed in inverted position to get back the white light

Fig.3. Dispersion of White Light through Prism

The phenomenon of a rainbow is also because of the dispersion of light.

Atmospheric Refraction

Twinkling of Stars

When a star is lit in the atmosphere, it has to undergo refraction. The refractive index changes and the light bends towards the normal. As a result, the actual position of the star is a little bit different from its apparent position. We also know that the atmosphere of the earth is not stationary, so changes in the apparent position of the stars occur. Thus, we see them twinkling in the sky or the Earth’s atmosphere.

Advance Sunlight and Delayed Sunset

Due to the phenomenon of atmospheric refraction, the sun is visible 2 minutes before the actual sunrise which is known as advanced sunlight. Just like the sunrise, the Sun is also visible 2 minutes after the actual sunset has taken place. This is known as Delayed Sunset.

Tyndall Effect

When a beam of light strikes tiny water droplets and suspended particles of dust the path of the beam becomes visible. This is Tyndall Effect. Fine particles scatter, particles of larger size scatter light of longer wavelengths.

Why does the sky appear blue?

The colour of the sky appears blue because of the scattering of light. When the sunlight passes through the atmosphere, the fine particles present in the air will scatter the blue colour since it has a shorter wavelength.

Why does the sky appear red during sunrise and sunset?

Fig.4. Reddening of Sun at rising and setting

When the Sun rises and sets, its light which is present near the horizon passes through thicker layers of atmosphere and travels larger distances before reaching our eye-sight. When the light of the Sun present overhead travels a comparatively shorter distance than light from the horizon, it results in the white appearance of the sun. Near the horizon, most of the blue light and shorter wavelengths are scattered by the particles. Therefore, the red light that reaches our eyes as it has the longest wavelength, hence the sky appears reddish.

Tips To Utilize CBSE Class 10 Maths CH 11 Notes

1. Conceptual Understanding: Concentrate on comprehending the fundamental concepts, formulas, and theorems described in the ch 11 maths class 10 notes.
2. Practice: Solve problems from your notes on a regular basis to improve your problem-solving abilities and become acquainted with various question types.
3. Identify Weak Areas: Identify and improve your weak areas by going over those sections in your physics class 10 chapter 11 notes pdf and practising more problems related to them.
4. Use Additional Resources: Supplement your learning with additional resources, such as reference books or online tutorials, to gain a better understanding of complex topics.
5. Regular Revision: Schedule regular revision sessions to strengthen your understanding of the chapter's concepts and improve your retention of the material.

Significance of NCERT Class 10 Science Chapter 11 Notes

Class 10 NCERT notes of Human Eye and Colourful World will be useful in revising the chapter and getting a sense of the key issues discussed. These NCERT Class 10 Science chapter 11 notes may also be used to cover the important concepts of the CBSE Science Syllabus in Class 10 as well as for competitive examinations such as NEET. These notes can also be downloaded in PDF format to study for the future also.

Class 10 Chapter Wise Notes

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• NCERT Solutions for Class 10 Maths
• NCERT Solutions for Class 10 Science

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• NCERT Exemplar Class 10 Maths solutions
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