NCERT Class 10 Science Science: Chapter 9 — Light - Reflection and Refraction
This chapter, "Light - Reflection and Refraction," from NCERT Class 10 Science, explores the fundamental properties of light. It begins by explaining how light enables us to see objects, with objects reflecting light that reaches our eyes. The chapter introduces the concept of light traveling in straight lines, evidenced by sharp shadows. It briefly touches upon diffraction and the dual nature of light (wave-particle duality) as studied in higher classes. The core focus is on the reflection of light by plane and spherical mirrors, recalling the laws of reflection. It also introduces refraction, the bending of light as it passes through different media. The chapter includes an activity using a spoon to demonstrate curved mirrors (concave and convex) and defines key terms like pole. This foundational knowledge is crucial for understanding various optical phenomena in nature and their applications.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 10 |
| Subject | Science |
| Book | Science |
| Chapter | Chapter 9 — Light - Reflection and Refraction |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 5 minutes |
| Word count | 824 |
Learning outcomes
- Understand how light enables vision and its straight-line propagation.
- Recall the laws of reflection of light.
- Identify and differentiate between concave and convex spherical mirrors.
- Define key terms related to spherical mirrors, such as the pole.
- Explore the formation of images by plane mirrors and curved surfaces.
Vocabulary
| Word | Meaning |
|---|---|
| Reflection | The bouncing back of light when it strikes a surface. |
| Refraction | The bending of light as it passes from one medium to another. |
| Ray of light | The straight-line path of light. |
| Diffraction | The bending of light around obstacles. |
| Spherical mirror | A mirror whose reflecting surface is a part of a sphere. |
| Concave mirror | A spherical mirror with its reflecting surface curved inwards. |
| Convex mirror | A spherical mirror with its reflecting surface curved outwards. |
| Pole | The center of the reflecting surface of a spherical mirror. |
| Virtual image | An image that cannot be projected onto a screen. |
| Erect image | An image that is upright relative to the object. |
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Practice questions
- What makes objects visible to us? Answer: Objects become visible when light falls on them and is reflected into our eyes.
- State the two laws of reflection of light. Answer: 1. The angle of incidence is equal to the angle of reflection. 2. The incident ray, the normal, and the reflected ray all lie in the same plane.
- What is a spherical mirror? Answer: A spherical mirror is a mirror whose reflecting surface is a part of the surface of a sphere.
- Differentiate between a concave and a convex mirror. Answer: A concave mirror has a reflecting surface curved inwards, while a convex mirror has a reflecting surface curved outwards.
- What is the pole of a spherical mirror? Answer: The pole is the center of the reflecting surface of a spherical mirror.
Frequently asked questions
What is the main concept discussed in NCERT Class 10 Science Chapter 9?
Chapter 9 of NCERT Class 10 Science focuses on the phenomena of reflection and refraction of light.
What are the two laws of reflection mentioned in the chapter?
The laws are: 1. Angle of incidence equals the angle of reflection. 2. Incident ray, normal, and reflected ray lie in the same plane.
How does the chapter explain the visibility of objects?
Objects are visible because they reflect light that falls on them, and this reflected light is received by our eyes.
What is the difference between a concave and a convex mirror?
A concave mirror's reflecting surface curves inward, while a convex mirror's reflecting surface curves outward.
What is the pole of a spherical mirror?
The pole is the central point of the reflecting surface of a spherical mirror.
What is the straight-line path of light called?
The straight-line path of light is usually indicated as a ray of light.
Related resources
Important topics
Topics covered
NCERT Class 10 Science — Science — Chapter 9 — Light - Reflection and Refraction. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.