Figure 1 shows some of the energy resources used to meet the demand for electrical power in the UK on one day in 2020 - AQA - GCSE Physics Combined Science - Question 1 - 2022 - Paper 1
Question 1
Figure 1 shows some of the energy resources used to meet the demand for electrical power in the UK on one day in 2020.
The maximum demand for electrical power on th... show full transcript
Worked Solution & Example Answer:Figure 1 shows some of the energy resources used to meet the demand for electrical power in the UK on one day in 2020 - AQA - GCSE Physics Combined Science - Question 1 - 2022 - Paper 1
Step 1
Determine the percentage of the maximum demand for electrical power that was generated using gas.
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Answer
To determine the percentage, we can observe from the graph that the maximum demand for electrical power at 6 pm is 30,000 GW, and the amount generated using gas is 16,500 GW. We can apply the formula:
Which energy resources need to be used to achieve this? Tick (✓) one box.
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Answer
The correct choice is:
Coal and gas ✓
Step 3
What is this network called?
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This network is called the national grid.
Step 4
Explain how using step-up transformers makes the network efficient.
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Answer
Step-up transformers improve the efficiency of the network by:
Increasing Potential Difference: They raise the voltage, which minimizes energy loss during transmission.
Reducing Current: As voltage increases, the current flowing through the cables decreases, which reduces heat generated due to resistance.
Lower Energy Loss: By reducing the current, less energy is lost as heat to the surroundings, allowing more efficient power transfer over long distances.