Science Class 6 - Light Shadows-And-Reflections Notes

Light, Shadows and Reflections

Welcome to the chapter on Light, Shadows and Reflections for Class 6. In this chapter, you will learn about light, how shadows are formed, and what reflections are. By the end of this chapter, you will understand how light travels, why shadows change shape, and how mirrors work!

Introduction

Light helps us see things around us. It comes from sources like the sun, bulbs, and candles. When light falls on objects, it can create shadows or reflections.

Sources of Light

• Natural sources: Sun, stars, fireflies.
• Artificial sources: Bulbs, candles, torches.

How Does Light Travel?

Light travels in a straight line. This is why shadows have sharp edges.

What are Shadows?

A shadow is formed when an object blocks light. The area behind the object where light cannot reach is called a shadow.

• Shadows are dark and have the shape of the object.
• Shadows change size and shape depending on the position of the light source.

What are Reflections?

Reflection happens when light bounces off a shiny surface like a mirror. We see our image in a mirror because of reflection.

• Smooth surfaces reflect light well.
• Rough surfaces scatter light in many directions.

Transparent, Translucent, and Opaque Objects

• Transparent: Let all light pass through (glass, clear water).
• Translucent: Let some light pass through (frosted glass, thin paper).
• Opaque: Do not let light pass through (wood, metal, stone).

Fun Activity: Shadow Play!

Use a torch and your hand to make shadow shapes on the wall. Try making animal shapes and see how the shadow changes when you move your hand closer or farther from the light.

Summary

• Light helps us see and comes from natural and artificial sources.
• Shadows are formed when objects block light.
• Reflections are seen in mirrors and shiny surfaces.
• Objects can be transparent, translucent, or opaque.

Practice Questions

1. Name two natural sources of light.
2. What is a shadow?
3. Why do we see our image in a mirror?
4. Give one example each of transparent, translucent, and opaque objects.
5. How does the position of the light source affect the shadow?

Challenge Yourself

• Draw a diagram showing how a shadow is formed.
• List three objects that reflect light well.

Did You Know?

• The moon shines because it reflects the light of the sun!
• Your shadow is shortest at noon when the sun is overhead.

Glossary

• Light: What helps us see things.
• Shadow: A dark area formed when something blocks light.
• Reflection: When light bounces off a surface.
• Transparent: Lets all light pass through.
• Opaque: Does not let light pass through.

Answers to Practice Questions

1. Sun, stars.
2. A shadow is a dark area formed when an object blocks light.
3. Because mirrors reflect light.
4. Transparent: glass; Translucent: frosted glass; Opaque: wood.
5. The shadow changes size and direction depending on where the light source is.

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Explore light, shadows, and reflections around you to discover the wonders of science!