Electricity

• Electricity is a flow of charges
• Conductors


  • Electricity can flow through conductors
  • Metals are good conductors of electricity
• Insulators


  • Electricity cannot flow through insulators
  • Plastics are good insulators
• Conditions for current to flow in a circuit

  1. A complete circuit with no gaps

  2. A cell or power supply
• Model for a circuit

  A central heating system represents a circuit
• Current is the amount of electricity flowing in the circuit
• Measuring current


  1. Use an ammeter

  2. Connect in series
• Units for current


  Amps (A)
• Voltage provides the 'push' and energy
• Measuring voltage


  1. Use a voltmeter

  2. Connect in parallel
• Units for voltage


  Volts (V)
• Resistance


  A way of saying how easy or difficult it is for electricity to flow
• High resistance


  Hard for electricity to flow = small current
• Low resistance


  Easy for electricity to flow = large current
• Thin wires and resistors

  • Have high resistances
• Thick wires


  • Have low resistances
• Electricity is a flow of charges
• Conductors


  • Electricity can flow through conductors
  • Metals are good conductors of electricity
• Insulators


  • Electricity cannot flow through insulators
  • Plastics are good insulators
• Conditions for current to flow in a circuit

  1. A complete circuit with no gaps

  2. A cell or power supply
• Model for a circuit

  A central heating system represents a circuit
• Current is the amount of electricity flowing in the circuit
• Measuring current


  1. Use an ammeter

  2. Connect in series
• Units for current


  Amps (A)
• Voltage provides the 'push' and energy
• Measuring voltage


  1. Use a voltmeter

  2. Connect in parallel
• Units for voltage


  Volts (V)
• Resistance


  A way of saying how easy or difficult it is for electricity to flow
• High resistance


  Hard for electricity to flow = small current
• Low resistance


  Easy for electricity to flow = large current
• Thin wires and resistors

  • Have high resistances
• Thick wires


  • Have low resistances
• Electricity is a flow of charges
• Conductors


  • Electricity can flow through conductors
  • Metals are good conductors of electricity
• Insulators


  • Electricity cannot flow through insulators
  • Plastics are good insulators
• Conditions for current to flow in a circuit

  1. A complete circuit with no gaps

  2. A cell or power supply
• Model for a circuit

  A central heating system represents a circuit
• Current is the amount of electricity flowing in the circuit
• Measuring current


  1. Use an ammeter

  2. Connect in series
• Units for current


  Amps (A)