GCSE Combined Science (AQA)
622 videos | 38 hours
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The National Grid
- The National Grid efficiently transports electricity from power stations to homes.
- Electricity is transported over distances of hundreds of miles.
- Generators in power stations generate alternating current at 1000 amps and 25,000 volts.
- Energy from various resources creates kinetic energy for an AC generator in power stations.
- Step up transformers increase potential difference to 400,000 volts and decrease current to 62.5 amps.
- Transformers change the potential difference of alternating current.
- A step up transformer increases voltage using two coils of wire wrapped around an iron core.
- High potential difference is used for transmission across long overhead cables to reduce energy loss.
- High overhead cables keep the dangerous high potential difference away from people.
- Step down transformers decrease potential difference to 230 volts for safe home use.
- Step down transformers are typically located at relay stations in towns.
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