2.3.2 Mains Electricity

• Mains electricity is supplied at a voltage of 230V
• The live wire in mains electricity is coloured brown and has a potential of 230V
• Match the wire with its function:

  Live wire ↔️ Carries electric current into the appliance

  Neutral wire ↔️ Completes the circuit, returning current to the power station

  Earth wire ↔️ Provides a safe route for fault current
• The earth wire is coloured green
• Order the steps in the flow of current in a properly wired appliance:

  1️⃣ Current enters the appliance through the live wire

  2️⃣ Appliance is powered

  3️⃣ Current returns to the power station through the neutral wire
• Mains electricity in the UK operates at a frequency of 50Hz
• A frequency of 50Hz means the current reverses direction 50 times each second
• Voltage measures the electric potential difference between the live and neutral wires
• Voltage is the electric potential difference between the live and neutral wires, measured in volts
• The frequency of mains electricity in the UK is 50Hz
• Match the wire with its function, colour, and potential:

  Live wire ↔️ Carries electric current into the appliance ||| Brown ||| 230V

  Neutral wire ↔️ Completes the circuit, returning current to the power station ||| Blue ||| 0V

  Earth wire ↔️ Provides a safe route for fault current ||| Green/Yellow ||| 0V
• What voltage does the live wire in mains electricity carry?

  230V
• The neutral wire completes the circuit and returns current to the power
• What color is the neutral wire in mains electricity?

  Blue
• Order the wires based on their function in mains electricity.

  1️⃣ Live wire carries current to the appliance

  2️⃣ Neutral wire completes the circuit

  3️⃣ Earth wire provides a safe route for fault current
• What is the purpose of fuses and circuit breakers in electrical circuits?

  Protect against fault currents
• A fuse breaks the circuit by melting a thin metal wire
• Match the component of mains electricity with its function.

  Live wire ↔️ Carries current

  Neutral wire ↔️ Completes the circuit

  Earth wire ↔️ Provides safe fault path
• Mains electricity in the UK operates at a voltage of 230V and a frequency of 50Hz.
• The frequency of mains electricity in the UK is 50Hz.
• What does earthing in electrical systems prevent?

  Electric shock
• Earthing ensures the metal casing of an appliance remains at or near earth potential.
• Why is double insulation considered safer than single insulation?

  No earth wire needed
• Appliances with double insulation do not require an earth wire.