1. GCSE Science A Physics 1 Transmission of Electricity Learning Outcomes Understand the need for an electrical distribution system Describe the national grid in terms of power stations, substations, and power lines. Understand the need for an electrical distribution system Describe the national grid in terms of power stations, substations, and power lines.

2. GCSE Science A Physics 1 Transmission of Electricity Key Words: Voltage: A type of electrical pressure, the “push” provided by a battery in a circuit. Current: The rate of flow of electricity Transformer: A device used to change the voltage in a circuit. Voltage: A type of electrical pressure, the “push” provided by a battery in a circuit. Current: The rate of flow of electricity Transformer: A device used to change the voltage in a circuit.

3. GCSE Science A Physics 1 Transmission of Electricity It would be a lot simpler if one power station met the electricity needs of all houses in the country, but what would be the problem with this plan?

4. GCSE Science A Physics 1 Transmission of Electricity The National Grid is a network of power cables, power stations, and transformers, around Britain. The National Grid connects all the power stations, and supplies electricity to all our houses and factories.

5. GCSE Science A Physics 1 Transmission of Electricity Therefore, if something goes wrong with one or more of the power stations, it is possible to get electricity from another source. Electricity is produced in the form of Alternating Current (A.C.). It is not possible to store this, therefore the supply has to answer the demand at all times.

6. GCSE Science A Physics 1 Transmission of Electricity How does a light bulb work??

7. GCSE Science A Physics 1 Transmission of Electricity How does a light bulb work?? Why don’t power lines glow?

8. GCSE Science A Physics 1 Transmission of Electricity Power station transformer houses 25 000V275 000V or 400 000V 240V As electric current flows through a wire, some energy is lost as heat – the higher the current the more heat is lost. Explain why this is a problem for companies producing electricity. How do they address this problem? Label the transformers – one raises the voltage, the other reduces it. Because of the relationship between electrical power, current and voltage, for the same power, if a small current is needed, then the voltage will be large.