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Which row in the table correctly describes how the national grid transfers electrical energy efficiently? Voltage Current Reason A High High To increase heating in wires - OCR Gateway - GCSE Physics - Question 10 - 2019 - Paper 1
Question 10
Which row in the table correctly describes how the national grid transfers electrical energy efficiently? Voltage Current Reason A High High To increase heating in ... show full transcript
Worked Solution & Example Answer:Which row in the table correctly describes how the national grid transfers electrical energy efficiently? Voltage Current Reason A High High To increase heating in wires - OCR Gateway - GCSE Physics - Question 10 - 2019 - Paper 1
Step 1
Which row in the table correctly describes how the national grid transfers electrical energy efficiently?
Answer
To determine which row describes the efficient transfer of electrical energy by the national grid, we must consider the principles of electrical transmission. The national grid uses high voltage and low current to minimize energy loss due to heating in the wires. A higher voltage allows electricity to be transmitted over long distances with less current, thereby reducing resistive losses, which can be described with the formula:
where is the power lost as heat, is the current, and is the resistance of the wires.
Thus, the correct answer that reflects this principle is:
B: High Voltage and Low Current - To reduce heating in wires.