Light - Reflection and Refraction

Chapter Overview

This chapter explains reflection and refraction of light, spherical mirrors, image formation, mirror formula, magnification, refraction through a glass slab, spherical lenses, lens formula, magnification and power of a lens.

Topics Covered

Reflection of Light

Laws of Reflection

Regular and Diffused Reflection

Spherical Mirrors

Concave Mirror

Convex Mirror

Pole and Centre of Curvature

Principal Axis

Principal Focus

Focal Length

Ray Diagrams

Mirror Formula

Magnification

Sign Convention

Refraction of Light

Laws of Refraction

Refractive Index

Refraction Through Glass Slab

Lateral Displacement

Spherical Lenses

Convex Lens

Concave Lens

Optical Centre

Principal Focus of Lens

Lens Formula

Magnification of Lens

Power of Lens

Sign Convention for Lenses

Numerical Problems

Quick Revision

Reflection is the bouncing back of light from a surface.
The angle of incidence is equal to the angle of reflection.
A concave mirror is a converging spherical mirror.
A convex mirror is a diverging spherical mirror.
Refraction is the change in direction of light when it passes obliquely from one transparent medium to another.
Refractive index describes the optical density of a medium relative to another medium or vacuum.
A convex lens is generally converging, while a concave lens is generally diverging for parallel rays.
Mirror and lens formulas are used to calculate image position and size.
Power of a lens is measured in dioptres.

Important Formulae

1/f = 1/v + 1/u

Mirror formula

m = hᵢ/hₒ = -v/u

Magnification for a spherical mirror

1/f = 1/v - 1/u

Lens formula

m = hᵢ/hₒ = v/u

Magnification for a lens

P = 1/f

Power of lens when focal length is in metres

Concave and Convex Mirrors

Feature	Concave Mirror	Convex Mirror
Nature	Converging	Diverging
Parallel Rays	Meet after reflection	Appear to diverge from focus
Common Uses	Shaving/makeup mirrors, headlights and some optical applications	Rear-view and side-view mirrors

Convex and Concave Lenses

Feature	Convex Lens	Concave Lens
Nature	Converging	Diverging
Parallel Rays	Converge towards focus	Diverge and appear to come from focus
Power	Positive	Negative

Official Study Sources

Use official NCERT and CBSE Academic resources for curriculum-aligned preparation.

NCERT Class 10 Science Textbook → CBSE Academic Curriculum 2026-27 → CBSE Assessment Resources →

Light - Reflection and Refraction

Chapter Overview

📘 Complete Notes

❓ Important Questions