GCSE physics Electricity

• Electricity is the subject of study known as electricity.
• Alternating current: The current goes in different directions, for example, the national grid.
• Live wire: brown, carries the alternating potential difference from the supply which is 230V.
• Direct current: The current goes in one direction, for example, the current produced by cells or batteries.
• The potential difference between the neutral and earth wire is 0v.
• Neutral wire: blue, completes the circuit and is at 0V.
• If the live and earth wire touch, it could cause a fire or shock because there is a high current.
• UKs mains supply: Frequency: 50Hz, Potential difference: 230v.
• Earth wire: yellow and green, is a safety wire to stop the appliance becoming live and is at 0V.
• A Step-down transformer has more coils on the primary coil than the secondary coil in the national grid.
• Power stations are a part of the national grid.
• The live wire is connected to the fuse in the national grid.
• Consumers are a part of the national grid.
• In a parallel circuit, the current is split between branches and the voltage is same everywhere.
• A step-up transformer has more coils on the secondary coil than the primary coil in the national grid.
• A step-down transformer is used in the national grid.
• Transformers are used to change potential difference and currents in transmission lines.
• In a series circuit, the current is same everywhere and the voltage is split between components.
• A step-up transformer is used in the national grid.
• High voltage transmission lines are a part of the national grid.