Class 7 Science Chapter 3 Electricity Circuits and Their Components Notes | Curiosity 2026-27 | Amresh Academy

 

🌟 Class 7 Science Curiosity – Chapter 3 Notes

⚡ Electricity: Circuits and their Components | Amresh Academy

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📘 Introduction

Electricity is an essential part of our daily life ⚡

👉 It helps us perform many activities easily and efficiently.

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🔌 1. Uses of Electricity

Electricity powers many devices:

• 🍳 Cooking → Microwave, induction
• 💡 Lighting → Bulbs, tube lights
• 🚆 Transportation → Electric trains
• ❄️ Heating/Cooling → AC, heater
• 📺 Entertainment → TV, speakers
• 📱 Communication → Mobile phones
• 💻 Others → Computers, laptops

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📊 Grouping of Uses:

• 🏠 By location → Home, school
• 🎯 By function → Daily needs, entertainment
• 🔋 By device type → Portable, fixed

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🔦 2. Torchlight and Its Components

A torchlight uses electricity from batteries to produce light 💡

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🔋 Components:

🔹 Electric Cell

• Portable source of electricity
• Has:
• Positive (+) terminal
• Negative (–) terminal

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🔹 Battery

• Two or more cells connected
• (+) of one → (–) of another
  👉 Gives more power ⚡

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🔹 Incandescent Lamp

• Contains a filament
• Glows when heated 🔥

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🔹 LED Lamp

• No filament
• Glows when current flows ✔️
• Long wire = Positive
• Short wire = Negative

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🔹 Switch

• Controls the circuit
  👉 ON = circuit complete
  👉 OFF = circuit broken

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🔄 3. Electrical Circuit

👉 A circuit is a complete path for electric current

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⚡ Important Points:

• Current flows only in closed circuit ✔️
• In open circuit, current stops ❌
• Direction: Positive → Negative

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📐 4. Circuit Diagrams

👉 Circuits are shown using symbols

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📌 Common Symbols:

• 🔋 Cell → Long line (+), short line (–)
• 💡 Lamp → Circle with filament
• 🔘 Switch → Line/gap
• 🔌 Wire → Straight line

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📌 Helps in easy understanding of circuits ✔️

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🧲 5. Conductors and Insulators

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⚡ Conductors:

👉 Allow current to pass

Examples:

• Copper
• Aluminium

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🚫 Insulators:

👉 Do NOT allow current

Examples:

• Plastic
• Rubber
• Wood

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🔌 Wires:

• Inside → Conductor (copper)
• Outside → Insulator (plastic)

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⚠️ Safety Tips:

• Body conducts electricity ⚡
• Avoid:
• Wet hands 💧
• Damaged wires

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🔋 6. Key Concepts

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⚡ Types of Current:

• 🔋 Direct Current (DC)
  👉 From batteries
• 🔌 Alternating Current (AC)
  👉 From wall sockets

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📌 Summary Points:

• Cells & batteries provide energy 🔋
• Lamps glow when current flows 💡
• Switch controls circuit 🔘
• Conductors & insulators ensure safety 🛡️

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📌 Final Summary

👉 This chapter helps you understand:

• Uses of electricity ⚡
• Circuit components 🔌
• Flow of current 🔄
• Safety precautions ⚠️

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