ull,{"backHref":"/gcse/physics/edexcel/questions","basePath":"/gcse/physics/edexcel/efficiency-and-energy-resources/questions","formulaUrl":null,"initialIndex":68,"initialQuestionWindow":[{"id":"d6369bba-de5d-4fcd-861b-d76aa72e64f1","revisionId":"1d828f09-fb42-4a9f-bd94-c9f921d7e80f","questionNumber":null,"questionType":"LA","specification":"Generating electricity using different energy resources produces different types of waste products that can damage the environment.\n\nState **one** harmful waste product produced by each of the following:","difficulty":6,"difficultyBand":"medium","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"f23582d7-f18f-40a9-abe6-2e10fd81dcfc","label":"a","content":"Burning natural gas","markscheme":"- States carbon dioxide ($CO_2$) or nitrogen oxides ($NO_x$) B1","marks":1,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"identify_combustion_waste","label":"Identify a combustion waste","steps":[{"type":"text","order":0,"title":"State one waste gas","content":"Burning natural gas produces **carbon dioxide**, $\\mathrm{CO_2}$, which is a harmful waste product because it contributes to global warming.\n\nState **carbon dioxide** for the **B1** mark. You only need one accepted product; nitrogen oxides, $\\mathrm{NO_x}$, would also be accepted.","highlights":[{"text":"Burning natural gas","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:47:09.885Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"2636ac32-0fbd-494f-b7a7-9187522608c8","label":"b","content":"Geothermal power generation","markscheme":"- States hydrogen sulfide ($H_2S$), greenhouse gases (such as carbon dioxide or methane) released from underground reservoirs, or geothermal brine containing heavy metals (e.g. arsenic or mercury) B1","marks":1,"order":1,"markingRubric":null,"explanation":{"methods":[{"id":"identify_geothermal_waste","label":"Identify a geothermal waste product","steps":[{"type":"text","order":1,"title":"State one waste product","content":"**Hydrogen sulfide ($H_2S$)** is a harmful gas that can be released from geothermal reservoirs. **[B1]**","highlights":[{"text":"Geothermal power generation","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:49:10.633Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"f5ab10a5-55c4-4271-ad8f-0bbbc972b34a","revisionId":"f8f39d4a-930e-4034-a08e-73f810b6384e","questionNumber":null,"questionType":"LA","specification":"A domestic solar photovoltaic array has an efficiency of 18%. During a clear afternoon, the array generates \$4.05 \\times 10^7\\text{ J}\$ of useful electrical energy.","difficulty":5,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"70d1963d-ad89-4fe5-9eeb-3dc97be9e8e0","label":null,"content":"Calculate the total solar energy incident on the array during this period.","markscheme":"- Correct rearrangement or substitution of numbers into the efficiency formula, e.g., $0.18 = \\frac{4.05 \\times 10^7}{\\text{total energy}}$ M1\n- Correct numerical calculation of $2.25 \\times 10^8$ (or $225\\ 000\\ 000$) A1\n- Correct unit ($\\text{J}$ or Joules, or $\\text{MJ}$ if answer is given as $225$) B1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"efficiency_rearrangement","label":"Use the efficiency equation","steps":[{"type":"drawing","order":0,"title":"Track the energy transfer","width":550,"height":396,"shapes":[{"id":"flow-node-incident","type":"line","color":"orange","points":[{"x":55.2,"y":90},{"x":493.3,"y":90},{"x":493.3,"y":42},{"x":55.2,"y":42},{"x":55.2,"y":90}]},{"id":"flow-node-array","type":"line","color":"blue","points":[{"x":42,"y":222},{"x":506.5,"y":222},{"x":506.5,"y":174},{"x":42,"y":174},{"x":42,"y":222}]},{"id":"flow-node-useful","type":"line","color":"green","points":[{"x":103.1,"y":354},{"x":445.4,"y":354},{

Efficiency and energy resources

Question 18

Efficiency and energy resources Questions

Efficiency and energy resources

Question 18

Efficiency and energy resources Questions