Electricity and Circuits

• Electricity

  • Definition: Flow of electric current
  • Importance: Runs appliances, provides light and heat
  • Source: Electric Cell

• Electric Cell

  • Source of electricity in small devices (torches, clocks)
  • Terminals
    • Positive terminal (+): Metal cap
    • Negative terminal (-): Metal disc
  • Working: Converts stored chemical energy into electrical energy

• Electric Bulb

  • Components
    • Filament: Thin wire that glows (made of tungsten)
    • Terminals: Two thick wires supporting the filament (base and metal tip)
    • Glass Chamber: Protects the filament (filled with inert gas)
  • Condition for glowing: Complete path for current

• Electric Circuit

  • Definition: Complete, closed path for electric current to flow
  • Components
    • Source: Electric Cell
    • Load: Electric Bulb / Appliance
    • Path: Wires
    • Control: Switch
  • Types of Circuits
    • Closed Circuit: Complete path, bulb glows
    • Open Circuit: Broken path, bulb does not glow

• Switch

  • Purpose: To turn the circuit ON or OFF
  • Mechanism: Connects or disconnects the gap in a circuit
  • Examples: Toggle switch, push button, knife switch

• Conductors and Insulators

  • Conductors
    • Definition: Materials that allow electricity to pass through them
    • Examples: Metals (copper, aluminum, iron), water with salts
  • Insulators
    • Definition: Materials that do not allow electricity to pass through them
    • Examples: Plastic, rubber, wood, glass, air

• Safety Precautions

  • Never touch switches or appliances with wet hands
  • Do not insert objects into electrical sockets
  • Use insulated tools and wires