4. Domestic uses and safety

Available for over a year

In this episode, Ellie Hurer and James Stewart explore the domestic uses of electricity and dissect the key features of a three-pin plug. They also discuss direct and alternating potential difference. Suitable for: AQA, Edexcel, OCR. For more information on domestic uses and safety, check out the BBC Bitesize website: https://www.bbc.co.uk/bitesize/guides/zw8n2nb/revision/2 Key learning objectives discussed in this episode: - Mains electricity is an AC supply. In the United Kingdom, the domestic electricity supply has a frequency of 50 Hz and is about 230 V. - Students should be able to explain the difference between direct and alternating potential difference. - Most electrical appliances are connected to the mains using three-core cable. - The insulation covering each wire is colour-coded for easy identification: - live wire – brown neutral wire – blue - earth wire – green and yellow stripes. - The live wire carries the alternating potential difference from the supply. The neutral wire completes the circuit. The earth wire is a safety wire to stop the appliance becoming live. - The potential difference between the live wire and the earth (0 V) is about 230 V. The neutral wire is at, or close to, earth potential (0 V). The earth wire is at 0 V, it only carries a current if there is a fault. - Students should be able to explain: - that a live wire may be dangerous even when a switch in the mains circuit is open - the dangers of providing any connection between the live wire and the earth.