Plane, Concave, and Convex Mirrors

Content Standards

In this lesson, students will understand the behavior of light when it reflects from different types of mirrors: plane, concave, and convex. They will explore how these mirrors form images and their applications in daily life.

Performance Standards

Students will be able to:

Identify the properties of plane, concave, and convex mirrors.
Demonstrate and explain image formation in each type of mirror.
Compare how different mirrors affect reflected light.
Connect the uses of mirrors to real-world applications (vehicles, telescopes, solar devices).

Alignment Standards

Reference: NCERT Book Alignment

The lesson is aligned with the NCERT Grade 8 Science Textbook, Chapter 10: Light: Mirrors and Lenses, Section: 10.3 – What Are the Laws of Reflection?

Learning Objectives

By the end of the lesson, students will be able to:

Identify plane, concave, and convex mirrors.
Explain how light behaves when it strikes each type of mirror.
Distinguish between converging and diverging reflections.
Apply the knowledge of mirrors to real-life contexts like shaving mirrors, rear-view mirrors, and solar cookers.

Prerequisites (Prior Knowledge)

Basic understanding of how light travels in straight lines.
Familiarity with the laws of reflection.

Introduction

In this session, students will explore how different types of mirrors change the direction of light. Using real-life examples, they will learn why car mirrors are curved, why telescopes use concave mirrors, and how solar cookers concentrate sunlight.

Timeline (40 Minutes)

Title	Approximate Duration	Procedure	Reference Material
Engage	5	Ask: “How does the shape of a mirror affect the reflection?” Briefly introduce mirror types.	Slides
Explore	10	Concentrating Light Energy: Activity Reflect sunlight onto paper using a concave mirror.	Slides
Explain	10	Explain types of mirror : Plane → parallel rays, same-size image Concave → converging rays, focal point Convex → diverging rays, wider view Virtual Lab Demo: Students watch how light rays behave on each mirror and visualise real-time convergence/divergence.	Slides and Virtual Lab
Evaluate	10	Students attempt the Self-Evaluation task on LMS.	Virtual Lab
Extend	5	Think–Pair–Share: “Where do we see a plane, concave, and convex mirrors in real life?”	Slides

Plane, Concave, and Convex Mirrors

Introduction

In this session, you will explore mirrors: plane, concave, and convex. You will also understand how different mirror types reflect light and their various uses in everyday life.

Theory

What are Mirrors?
A mirror is a polished surface that reflects light to form an image. Mirrors follow the laws of reflection, but the type of image depends on the mirror’s shape.

Plane Mirror

Flat reflecting surface.
Parallel rays remain parallel after reflection.
Forms virtual, upright, and laterally inverted images of the same size.
Example: everyday bathroom mirrors, periscopes.

Concave Mirror

Curved inward (like the inside of a spoon).
Parallel rays of light converge at a point called the focus.
Forms either real or virtual images, depending on distance.
Example: dentist’s mirrors, solar cookers, telescopes, headlights.

Convex Mirror

Curved outward (like the back of a spoon).
Parallel rays of light diverge after reflection.
Image appears to come from behind the mirror: always virtual, upright, and smaller.
Example: vehicle rearview mirrors, shop security mirrors.

Activity 1: Beams of Light and Mirrors

A torch with comb slits produces multiple parallel beams.
Plane mirror → reflected beams stay parallel.
Concave mirror → beams converge.
Convex mirror → beams diverge.

Activity 2: Burning Paper with Concave Mirror

A concave mirror reflects sunlight onto paper.
Light converges at a point → bright spot → generates heat → burns paper.
Explains how solar concentrators work.

Applications

Plane mirrors: daily use, instruments like periscopes.
Concave mirrors: solar cookers, headlights, magnifying devices.
Convex mirrors: rearview mirrors, surveillance.

Vocabulary

This is the list of vocabulary terms used throughout the lesson.

Reflection – The bouncing back of light from a surface.
Plane Mirror – A flat mirror that reflects parallel rays as parallel rays.
Concave Mirror – A mirror curved inward that converges light rays.
Convex Mirror – A mirror curved outward that diverges light rays.
Focus – The point where parallel rays meet after reflection (in concave).
Virtual Image – An image that cannot be projected on a screen.
Real Image – An image that can be projected on a screen.
Converge – To come together at a point.
Diverge – To spread apart.
Solar Concentrator – A device using mirrors to concentrate sunlight to produce heat or energy.

Plane, Concave, and Convex Mirrors

Introduction

Welcome to the Virtual Lab on Light and Mirrors! In this immersive VR experience, students will visualize how light behaves when it falls on plane, concave, and convex mirrors. Explore interactive 3D simulations to observe reflection patterns, compare how light converges or diverges, and understand image formation in real time. Connect these concepts to real-life applications like vehicles and telescopes and test your knowledge with a quick quiz.

Key Features

Animated simulation of plane, concave, and convex lenses.
Visualization of light bending through each lens.
Demonstration of image formation (real vs virtual).
Automatic update of light paths and images.
Embedded short quiz (2 MCQs) for quick reinforcement.

Step-by-Step Procedure for VR Experience

Step 1 – Open the Virtual Lab
Students access the 3D simulation of mirrors.
Step 2 – Plane Mirror Scene
Watch parallel light beams reflect and remain parallel, forming upright images.
Step 3 – Concave Mirror Scene
Observe parallel light beams converge at a point, showing how concave mirrors concentrate light.
Step 4 – Convex Mirror Scene
See parallel light beams diverge after reflection, with images appearing smaller and virtual.
Step 5 – Comparison Mode
View all three types of mirrors side by side for clear differences.
Step 6 – Quiz and Feedback
Answer 2 MCQs at the end to test understanding and receive instant feedback.