Electricity

• Electricity


  A form of energy generated by the movement of charged particles, such as electrons
• Static electricity


  The accumulation of electric charge on the surface of an object
• Production of static electricity

  1. Friction

  2. Contact

  3. Induction
• Uses of static electricity

  • Photocopiers and laser printers
  • Air purifiers
  • Paint spraying
  • Textile industry
  • Photography
• Electrical current (I)


  The flow of electric charge through a conductor
• Voltage (V)


  The measure of electric potential difference between two points in a circuit
• Resistance (R)


  The opposition to the flow of electric current in a conductor
• The main source of energy used in homes in Jamaica is electricity, typically provided by the national grid or renewable energy sources such as solar panels
• Conductors


  Materials that allow electricity to flow through them easily due to the presence of free moving electrons
• Insulators


  Materials that inhibit the flow of electricity due to their tightly bound electrons
• Examples of conductors

  • Metals (e.g., copper, aluminum, silver)
  • Graphite (a form of carbon)
  • Saltwater (when dissolved in water)
  • Human body (due to the presence of electrolytes)
• Insulators


  • Rubber
  • Plastic
  • Glass
  • Wood
• Electrical circuit


  A system that is connected to a power source/supply and forms a closed loop or pathway through which electric current flows
• Components of an electrical circuit

  • Voltage source/battery
  • Wires
  • Switches
  • Resistors
  • Capacitors
  • Inductors
  • Diodes
  • Transistors
  • Fuse
  • Voltmeter
  • Ammeter
• Series circuit


  Components are connected end-to-end, forming a single pathway for current flow
• Parallel circuit


  Components are connected across multiple paths, allowing current to flow through each component independently
• Advantages of series circuits

  • Simplicity
  • Cost-effective
  • Voltage division
  • Current limitation
• Disadvantages of series circuits

  • Voltage drop
  • Component failure
  • Brightness decreases
• Advantages of parallel circuits

  • Reliability
  • Brightness consistency
  • Flexibility
  • Reduced voltage drop
• Disadvantages of parallel circuits

  • Complexity
  • Cost
  • Current division
  • Power source limitation
• Series circuit examples


  • Christmas lights
  • Flashlight
  • Electrical wiring in a building
• Parallel circuit examples


  • Household electrical outlets
  • Car electrical system
  • Electronic devices
  • Christmas tree lights (modern LED)
• Ohm's Law


  V = I × R, where V is voltage, I is current, and R is resistance
• Calculating total resistance

  1. For resistors in series: Rtotal = R1 + R2 + R3 + ...

  2. For resistors in parallel: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 + ...
• Current =

  Voltage (V) ÷ Resistance (R)
• Resistance =

  Voltage (V) ÷ Current (I)