🌟 Introduction

Human Eye and the Colourful World is one of the most important chapters in the Class 10 CBSE Science syllabus. For students preparing for CBSE Board examinations, solving Previous Year Questions (PYQs) is the most effective way to understand the exam pattern, marking scheme, and frequently repeated themes. At Dhingra Classes Nashik, we have compiled the most important PYQs from this chapter, organized by marks weightage, to help Class 10 students score maximum marks.

This chapter covers the Human Eye, Accommodation, Defects of Vision, Myopia, Hypermetropia, Presbyopia, Cataract, Refraction through a Prism, Dispersion of Light, Atmospheric Refraction, Scattering of Light, Tyndall Effect, and Rainbow Formation. These PYQs have been collected from CBSE Board exams across multiple years and are essential for effective board exam preparation.

📚 Why Solving PYQs Is Important for CBSE Class 10

Before diving into the questions, let us understand why Previous Year Questions are crucial for Class 10 CBSE students.

🎯 Benefits of Solving PYQs

• ✅ Understanding Exam Pattern: PYQs reveal how questions are framed

• 📝 Identifying Repeated Themes: Many questions repeat with slight variations

• 🧠 Better Answer Writing: PYQs help practice structured answers

• 🏆 Higher Scores: Familiarity with question types reduces exam stress

• 📊 Time Management: Practice helps allocate time per question correctly

• 👁️ Diagram Practice: Many PYQs require drawing and labeling eye diagrams

📖 1 Mark Questions (Very Short Answer Type)

These questions are typically asked as MCQs, Assertion-Reason, or one-line answers. They test factual knowledge and basic understanding.

Set A: MCQs and One-Line Answers

Set B: Assertion-Reason Questions

Question 1: Assertion (A): The sky appears blue to us. Reason (R): Blue light is scattered more than red light by air molecules.
Answer: Both A and R are true and R is the correct explanation of A.

Question 2: Assertion (A): The Sun appears reddish at sunrise and sunset. Reason (R): Red light is scattered the most by air molecules.
Answer: (c) A is true but R is false.

📖 2 Marks Questions (Short Answer Type I)

These questions require two points or brief explanations and are designed to test conceptual understanding.

Question 1: What is meant by the power of accommodation of the eye?

Answer:

• The power of accommodation is the ability of the eye to focus on both near and distant objects by changing the focal length of the lens.

• The ciliary muscles adjust the curvature of the eye lens to achieve this.

Question 2: Why do we have two eyes for vision and not just one?

Answer:

• Two eyes provide a wider field of view (about 180° instead of 150°).

• Two eyes give stereoscopic vision, which helps in judging distances accurately.

Question 3: What is myopia? How is it corrected?

Answer:

• Myopia is short-sightedness, where a person can see nearby objects clearly but not distant objects.

• It is corrected by using a concave lens of appropriate power.

Question 4: What is hypermetropia? How is it corrected?

Answer:

• Hypermetropia is long-sightedness, where a person can see distant objects clearly but not nearby objects.

• It is corrected by using a convex lens of appropriate power.

Question 5: Why does the sky appear blue?

Answer:

• Blue light has a shorter wavelength and is scattered more than red light by air molecules.

• This scattered blue light reaches our eyes, making the sky appear blue.

Question 6: Why does the Sun appear reddish at sunrise and sunset?

Answer:

• At sunrise and sunset, light from the Sun has to travel a longer distance through the atmosphere.

• Most of the blue light is scattered away, and only red light reaches our eyes.

Question 7: What is the Tyndall effect? Give one example.

Answer:

• The Tyndall effect is the scattering of light by colloidal particles.

• Example: Sunlight passing through a canopy of dense forest shows the Tyndall effect.

Question 8: What is a cataract? How is it corrected?

Answer:

• A cataract is a condition where the eye lens becomes cloudy, leading to blurred vision.

• It is corrected by cataract surgery, where the cloudy lens is replaced with an artificial lens.

📖 3 Marks Questions (Short Answer Type II)

These questions require detailed explanations with three distinct points and test analytical understanding.

Question 1: Explain the structure and function of the human eye.

Answer:

• The human eye has parts like the cornea, iris, pupil, lens, and retina.

• The cornea refracts light, the iris controls pupil size, and the lens focuses light on the retina.

• The retina contains photoreceptors (rods and cones) that convert light into nerve impulses, which are sent to the brain via the optic nerve.

Question 2: Explain the defects of vision and their corrections.

Answer:

• Myopia: Short-sightedness; corrected by concave lens.

• Hypermetropia: Long-sightedness; corrected by convex lens.

• Presbyopia: Age-related loss of accommodation; corrected by bifocal lenses.

Question 3: Explain the dispersion of light with the help of a prism.

Answer:

• Dispersion is the splitting of white light into its component colours.

• When white light passes through a glass prism, it bends at different angles for different colours.

• This produces a spectrum of seven colours (VIBGYOR) on a screen.

Question 4: Explain the formation of a rainbow.

Answer:

• A rainbow is formed by the dispersion of sunlight by water droplets in the atmosphere.

• Sunlight enters a droplet, is refracted, dispersed, and internally reflected, then refracted again.

• This produces a spectrum of colours in the form of a rainbow.

Question 5: Explain the scattering of light with examples.

Answer:

• Scattering is the redirection of light by particles in its path.

• Blue sky: Blue light is scattered more by air molecules.

• Red sunset: Red light travels longer distances and reaches our eyes after blue light is scattered.

Question 6: Explain the structure and function of the retina.

Answer:

• The retina is the innermost layer of the eye containing photoreceptors.

• Rods are sensitive to dim light, while cones are sensitive to bright light and colour.

• The retina converts light into electrical signals that are sent to the brain via the optic nerve.

Question 7: Explain the phenomenon of atmospheric refraction.

Answer:

• Atmospheric refraction is the bending of light due to variations in air density.

• It causes the twinkling of stars and the apparent flattening of the Sun at sunrise and sunset.

• It also causes advanced sunrise and delayed sunset.

Question 8: Explain the importance of the human eye.

Answer:

• The human eye is a valuable sense organ that helps us see the world.

• It enables us to perceive colours, shapes, and distances.

• It plays a crucial role in learning, communication, and survival.

Question 9: Explain the defects of vision in human beings and their corrections.

Answer:

• Myopia: Short-sightedness; corrected by concave lens.

• Hypermetropia: Long-sightedness; corrected by convex lens.

• Presbyopia: Age-related loss of accommodation; corrected by bifocal lenses.

Question 10: Explain the phenomenon of dispersion of light with examples.

Answer:

• Dispersion is the splitting of white light into its component colours.

• It occurs because different colours refract at different angles.

• Examples: Rainbow formation and spectrum produced by a prism.

Question 11: Explain the Tyndall effect with examples.

Answer:

• The Tyndall effect is the scattering of light by colloidal particles.

• It makes the path of a beam of light visible in a colloid.

• Examples: Sunlight passing through a canopy of dense forest and light passing through a dusty room.

Question 12: Explain the concept of the least distance of distinct vision.

Answer:

• The least distance of distinct vision is the minimum distance at which the eye can see an object clearly.

• For a normal human eye, it is 25 cm.

• It is important for reading and other close work.

📖 5 Marks Questions (Long Answer Type)

These questions require comprehensive answers with five distinct points and test in-depth understanding and analytical skills.

Question 1: Explain the structure and function of the human eye with the help of a diagram.

Answer:

• The human eye has parts like the cornea, iris, pupil, lens, and retina.

• The cornea refracts light, the iris controls pupil size, and the lens focuses light on the retina.

• The retina contains photoreceptors (rods and cones) that convert light into nerve impulses.

• The optic nerve carries impulses to the brain, which interprets them as images.

• The eye is protected by the sclera and nourished by the choroid.

Question 2: Explain the defects of vision and their corrections with diagrams.

Answer:

• Myopia: Short-sightedness; the image forms in front of the retina; corrected by concave lens.

• Hypermetropia: Long-sightedness; the image forms behind the retina; corrected by convex lens.

• Presbyopia: Age-related loss of accommodation; corrected by bifocal lenses.

• Cataract: Clouding of the eye lens; corrected by cataract surgery.

• Astigmatism: Irregular curvature of the cornea; corrected by cylindrical lenses.

Question 3: Explain the dispersion of light with the help of a prism and the formation of a spectrum.

Answer:

• Dispersion is the splitting of white light into its component colours.

• When white light passes through a glass prism, it bends at different angles for different colours.

• This produces a spectrum of seven colours (VIBGYOR) on a screen.

• Red bends the least, and violet bends the most.

• The refractive index of the prism material is different for different colours.

Question 4: Explain the formation of a rainbow with the help of a diagram.

Answer:

• A rainbow is formed by the dispersion of sunlight by water droplets in the atmosphere.

• Sunlight enters a droplet, is refracted, dispersed, and internally reflected, then refracted again.

• This produces a spectrum of colours in the form of a rainbow.

• The red colour appears on the outer edge, and violet on the inner edge.

• A rainbow is always formed in the direction opposite to the Sun.

Question 5: Explain the scattering of light and its applications in daily life.

Answer:

• Scattering is the redirection of light by particles in its path.

• Blue sky: Blue light is scattered more by air molecules.

• Red sunset: Red light travels longer distances and reaches our eyes after blue light is scattered.

• Danger signals: Red is used because it is scattered the least and can be seen from far.

• Tyndall effect: Scattering of light by colloidal particles makes the path of light visible.

Question 6: Explain the phenomenon of atmospheric refraction and its effects.

Answer:

• Atmospheric refraction is the bending of light due to variations in air density.

• It causes the twinkling of stars and the apparent flattening of the Sun at sunrise and sunset.

• It also causes advanced sunrise and delayed sunset.

• Stars appear to twinkle because their light passes through turbulent layers of the atmosphere.

• Planets do not twinkle because they are closer and appear as extended sources.

Question 7: Explain the structure and function of the retina with the help of a diagram.

Answer:

• The retina is the innermost layer of the eye containing photoreceptors.

• Rods are sensitive to dim light, while cones are sensitive to bright light and colour.

• The retina converts light into electrical signals that are sent to the brain via the optic nerve.

• The fovea is the region of sharpest vision, containing only cones.

• The blind spot is the region where the optic nerve leaves the eye, containing no photoreceptors.

Question 8: Explain the concept of the power of accommodation and its importance.

Answer:

• The power of accommodation is the ability of the eye to focus on both near and distant objects.

• The ciliary muscles adjust the curvature of the eye lens to achieve this.

• It is important for reading, writing, and other close work.

• The least distance of distinct vision is 25 cm for a normal eye.

• The far point of a normal eye is infinity.

Question 9: Explain the defects of vision in human beings and their corrections.

Answer:

• Myopia: Short-sightedness; corrected by concave lens.

• Hypermetropia: Long-sightedness; corrected by convex lens.

• Presbyopia: Age-related loss of accommodation; corrected by bifocal lenses.

• Cataract: Clouding of the eye lens; corrected by cataract surgery.

• Astigmatism: Irregular curvature of the cornea; corrected by cylindrical lenses.

Question 10: Explain the phenomenon of dispersion of light with examples.

Answer:

• Dispersion is the splitting of white light into its component colours.

• It occurs because different colours refract at different angles.

• Examples: Rainbow formation and spectrum produced by a prism.

• The red colour bends the least, and violet bends the most.

• The refractive index of the prism material is different for different colours.

Question 11: Explain the Tyndall effect with examples.

Answer:

• The Tyndall effect is the scattering of light by colloidal particles.

• It makes the path of a beam of light visible in a colloid.

• Examples: Sunlight passing through a canopy of dense forest and light passing through a dusty room.

• It is used to distinguish between a true solution and a colloid.

• It is also responsible for the blue colour of the sky.

Question 12: Explain the concept of the least distance of distinct vision and its importance.

Answer:

• The least distance of distinct vision is the minimum distance at which the eye can see an object clearly.

• For a normal human eye, it is 25 cm.

• It is important for reading and other close work.

• It increases with age due to loss of accommodation.

• It is used to determine the power of corrective lenses.

📝 How to Use These PYQs for CBSE Exam Preparation

At Dhingra Classes Nashik, we recommend the following strategies to maximize your score using these PYQs.

🎯 Study Tips

1. 📖 Read each question and try to answer before looking at the solution

2. ✏️ Practice writing answers within time limits (1 mark = 1 min, 3 marks = 5 min, 5 marks = 10 min)

3. 🗣️ Focus on repeated themes like defects of vision, dispersion, and scattering of light

4. 📝 Create flashcards for 1-mark questions

5. 👁️ Practice diagrams for the human eye, prism, and rainbow formation

6. 🔄 Revise weekly to ensure long-term retention

7. 📋 Practice Assertion-Reason questions as they are frequently asked

8. ✅ Take mock tests using these PYQs

🏫 How Dhingra Classes Nashik Helps Class 10 CBSE Students Master Science

At Dhingra Classes Nashik, we provide comprehensive coaching for Science and all other subjects for Class 10 CBSE students. Our approach includes:

• 📚 Structured Lessons: Teaching concepts with clear explanations

• 👁️ Diagram Practice: Regular diagram work for better understanding

• 📝 PYQ Analysis: Regular practice with previous year questions

• ✏️ Regular Tests: Weekly tests to ensure continuous revision

• 🎯 Doubt Clearing Sessions: Personalized attention to every student

• 📊 Progress Tracking: Regular updates to parents about student progress

• 🏆 Answer Writing Practice: Teaching how to structure answers for maximum marks

📞 Contact Dhingra Classes Nashik

• 📱 Phone: 98230 62106

• 📧 Email: dhingraclassesnsk@gmail.com

• 🌐 Website: www.dhingraclassesnashik.com

• 📍 Address: Plot No 3, XQ3G+H3M Deacon Homes, 301C, opp. Metro Zone, near Guru Govind Sing, Samarth Nagar, Dnyaneshwar Nagar, Pathardi Phata, Nashik, Maharashtra 422009

🏁 Conclusion

Mastering Human Eye and the Colourful World PYQs is essential for Class 10 CBSE students to score high marks in Science board examinations. This comprehensive collection of 1-mark, 2-mark, 3-mark, and 5-mark questions covers all major themes including Human Eye, Accommodation, Defects of Vision, Myopia, Hypermetropia, Presbyopia, Cataract, Refraction through a Prism, Dispersion of Light, Atmospheric Refraction, Scattering of Light, Tyndall Effect, and Rainbow Formation.

By regularly practicing these Previous Year Questions and using them in your board exam preparation, you can improve your understanding and score better. At Dhingra Classes Nashik, we are committed to helping Class 10 CBSE students excel in Science and achieve academic success. Remember, Human Eye and the Colourful World is not just about memorizing facts—it is about understanding how we see the world and how light creates the beautiful phenomena around us.