ЁЯМЯ Class 7 Science Curiosity – Chapter 11 Notes
ЁЯФж Light: Shadows and Reflections | Amresh Academy
ЁЯУШ Introduction
ЁЯТб 1. Sources of Light
ЁЯФЖ Luminous Objects:
ЁЯСЙ Produce their own light
- ☀️ Sun
- ⭐ Stars
- ЁЯРЮ Fireflies
- ЁЯТб Bulbs
ЁЯМЩ Non-Luminous Objects:
- ЁЯМЩ Moon
ЁЯМ┐ Types of Sources:
- ЁЯМЮ Natural → Sun, stars, lightning
- ЁЯХп️ Artificial → Candle, bulb, LED
⚡ LED Lamps:
- Energy efficient ЁЯТб
- Long-lasting
- Eco-friendly ЁЯМН
ЁЯУП 2. Light Travels in a Straight Line
ЁЯзк Experiments:
- ЁЯУж Matchbox → Light passes through aligned holes
- ЁЯФз Pipe → Straight pipe shows flame, bent pipe doesn’t
- ЁЯФ┤ Laser → Moves straight even in water
ЁЯз▒ 3. Light and Materials
ЁЯФН Types:
✔️ Transparent:
ЁЯСЙ Light passes completely
- Glass
ЁЯМл️ Translucent:
ЁЯСЙ Light passes partially
- Tracing paper
❌ Opaque:
ЁЯСЙ Light is blocked
- Cardboard
ЁЯМС 4. Shadow Formation
ЁЯУМ Shadow:
ЁЯСЙ Dark region formed when light is blocked
ЁЯФС Requirements:
- Light source ЁЯТб
- Opaque object ЁЯз▒
- Screen (wall)
ЁЯза Observations:
- Opaque → dark shadow
- Translucent → light shadow
- Size depends on position
- Color doesn’t affect shadow
ЁЯкЮ 5. Reflection of Light
ЁЯУМ Definition:
ЁЯСЙ Light bounces back from a surface
ЁЯФН Example:
- Mirror ЁЯкЮ
- Shiny surfaces
ЁЯкЮ 6. Images in a Plane Mirror
ЁЯУК Properties:
- Same size ЁЯУП
- Upright (erect) ✔️
- Virtual image
- Laterally inverted ЁЯФД (left-right reversed)
ЁЯЪС Example:
ЁЯСЙ “AMBULANCE” appears reversed in mirror
ЁЯУ╖ 7. Pinhole Camera
ЁЯУМ Definition:
ЁЯСЙ Device that forms image through a small hole
ЁЯза Image Properties:
- Inverted (upside down) ЁЯФД
- Shows colors ЁЯОи
ЁЯЫа️ Construction:
- Cardboard box
- Small hole
- Screen
ЁЯФН 8. Useful Devices
ЁЯФн Periscope:
- Uses mirrors
- Helps see around corners
ЁЯОи Kaleidoscope:
- Uses mirrors
- Creates beautiful patterns
ЁЯУМ Final Summary
ЁЯСЙ Light helps us understand:
- Shadows ЁЯМС
- Reflection ЁЯкЮ
- Images ЁЯУ╖
ЁЯФС Key Concepts:
- Light travels straight ЁЯУП
- Materials affect light ЁЯз▒
- Mirrors form images ЁЯкЮ
- Devices use reflection ЁЯФн
✨ Perfect for revision + exams + concept clarity ЁЯЪА
