🌟 Class
7 Science Curiosity – Chapter 11 Notes
🔦 Light:
Shadows and Reflections | Amresh Academy
📘
Introduction
💡 1.
Sources of Light
🔆
Luminous Objects:
👉
Produce their own light
- ☀️ Sun
- ⭐ Stars
- 🐞
Fireflies
- 💡
Bulbs
🌙
Non-Luminous Objects:
- 🌙
Moon
🌿 Types
of Sources:
- 🌞
Natural → Sun, stars, lightning
- 🕯️
Artificial → Candle, bulb, LED
⚡ LED
Lamps:
- Energy
efficient 💡
- Long-lasting
- Eco-friendly
🌍
📏 2.
Light Travels in a Straight Line
🧪
Experiments:
- 📦
Matchbox → Light passes through aligned holes
- 🔧
Pipe → Straight pipe shows flame, bent pipe
doesn’t
- 🔴
Laser → Moves straight even in water
🧱 3.
Light and Materials
🔍 Types:
✔️
Transparent:
👉 Light
passes completely
- Glass
🌫️
Translucent:
👉 Light
passes partially
- Tracing
paper
❌
Opaque:
👉 Light
is blocked
- Cardboard
🌑 4.
Shadow Formation
📌
Shadow:
👉 Dark
region formed when light is blocked
🔑
Requirements:
- Light
source 💡
- Opaque
object 🧱
- Screen
(wall)
🧠
Observations:
- Opaque
→
dark shadow
- Translucent
→
light shadow
- Size
depends on position
- Color
doesn’t affect shadow
🪞 5.
Reflection of Light
📌
Definition:
👉 Light
bounces back from a surface
🔍
Example:
- Mirror
🪞
- Shiny
surfaces
🪞 6.
Images in a Plane Mirror
📊
Properties:
- Same
size 📏
- Upright
(erect) ✔️
- Virtual
image
- Laterally
inverted 🔄
(left-right reversed)
🚑
Example:
👉
“AMBULANCE” appears reversed in mirror
📷 7.
Pinhole Camera
📌
Definition:
👉 Device
that forms image through a small hole
🧠 Image
Properties:
- Inverted
(upside down) 🔄
- Shows
colors 🎨
🛠️
Construction:
- Cardboard
box
- Small
hole
- Screen
🔍 8.
Useful Devices
🔭
Periscope:
- Uses
mirrors
- Helps
see around corners
🎨
Kaleidoscope:
- Uses
mirrors
- Creates
beautiful patterns
📌 Final
Summary
👉 Light
helps us understand:
- Shadows
🌑
- Reflection
🪞
- Images
📷
🔑 Key
Concepts:
- Light
travels straight 📏
- Materials
affect light 🧱
- Mirrors
form images 🪞
- Devices
use reflection 🔭
✨ Perfect
for revision + exams + concept clarity 🚀
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