gy. Stating this equation earns the method mark."},{"type":"text","order":4,"title":"State the efficiency conclusion","content":"Therefore, transmitting at a high voltage gives a lower current. The cables then waste less energy as thermal energy (heating), so a greater fraction of the input electrical energy reaches consumers: the transfer is more efficient.\n\nThis clear link from lower current to less heating loss earns the final mark.","highlights":[{"text":"Explain why it is more efficient to transfer electrical energy at high voltages.","location":"specification"}]}]}],"generatedAt":"2026-07-21T18:04:04.515Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"718de89c-7818-4003-acaa-fe21e5c190f5","label":"c","content":"A section of transmission line has a power loss of \$11.25\\text{ kW}\$ and a resistance of \$12.5\\ \\Omega\$.\n\nCalculate the current in this transmission line.","markscheme":"- Converts power to watts: $P = 11250\\text{ W}$ B1\n- Uses $P = I^2 R$ to state $I = \\sqrt{\\frac{P}{R}}$ M1\n- Substitutes values to find $I^2 = \\frac{11250}{12.5} = 900$ A1\n- Calculates the final current $I = 30\\text{ A}$ A1","marks":4,"order":2,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"4b65bc58-255c-48e9-906f-54535e91f4eb","revisionId":"c041b1b3-4a19-401d-8e18-cc43f7f5bb94","questionNumber":null,"questionType":"LA","specification":"The pie chart shows how electricity was generated in a region in 2025.\n\n![A pie chart representing the electricity generation mix of a region in 2025.](https://assets.mathsgenie.co.uk/aqa-qb/2ba3f19e-36a8-40ad-ac20-c0888a47103d.png)","difficulty":3,"difficultyBand":"medium","totalMarks":7,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"bbd1911f-fab7-488a-a7b3-963a7db97495","label":"a","content":"Which **two** energy resources generated the least electricity in 2025?","markscheme":"- Identifies Geothermal as the smallest percentage ($2\\%$) and Solar as the second smallest ($4.6\\%$) M1\n- Concludes the two lowest resources are Geothermal and Solar A1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"read_pie_chart","label":"Read the pie chart","steps":[{"type":"text","order":0,"title":"Compare the percentages","content":"Look at the percentages written on the chart. The smallest is Geothermal at $2\\%$, and the next smallest is Solar at $4.6\\%$.\n\nThis comparison earns **M1**.","highlights":[{"text":"Which **two** energy resources generated the least electricity in 2025?","location":"specification"}]},{"type":"text","order":1,"title":"State both resources","content":"Therefore, the two energy resources that generated the least electricity were **Geothermal** and **Solar**.\n\nNaming both resources clearly earns **A1**."}]}],"generatedAt":"2026-07-22T12:13:03.749Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"15945ffe-ece9-4741-bea3-cb980f0d7f11","label":"b","content":"Estimate the percentage of electricity generated using hydroelectric power in 2025.","markscheme":"- Recognises that the sector for hydroelectric power is bounded by perpendicular lines representing a right angle ($90^\\circ$ or $\\frac{1}{4}$ of the circle) M1\n- Calculates the estimated percentage as $25\\%$ A1","marks":2,"order":1,"markingRubric":null,"explanation":{"methods":[{"id":"right_angle_sector","label":"Use the right-angle sector","steps":[{"type":"text","order":0,"title":"Inspect the hydroelectric sector","content":"Look at the two straight radii that bound the **Hydroelectric** sector: one points vertically upwards and the other horizontally to the right. These lines are perpendicular, so the sector is a right angle.\n\nRecognising this earns the **M1** mark.","highlights":[{"text":"Estimate the percentage of electricity generated using hydroelectric power in 2025.","location":"specification"

Powering Earth

Question 8

Powering Earth Questions

Powering Earth

Question 8

Powering Earth Questions