nd record the initial temperature of the water in each tube before switching on the heater. The initial temperatures need to be known so that each temperature increase can be found.\n\nThis earns **M1**.","highlights":[{"text":"Both tubes contain the same volume of water at the same initial temperature.","location":"specification"}]},{"type":"text","order":2,"title":"Heat for equal time","content":"Switch on the heater and start the stopwatch at the same time. After a fixed time interval, measure and record the temperature of the water in both tubes. Alternatively, record both temperatures at regular equal time intervals.\n\nThis earns **M1**.","highlights":[{"text":"a radiant source of heat, and other laboratory equipment.","location":"specification"}]},{"type":"hyper_latex","block":{"nodes":[{"latex":"\\htmlData{anchor=rise-black}{\\Delta T_{\\mathrm{black}}}=T_{\\mathrm{final,black}}-T_{\\mathrm{initial,black}}"},{"latex":"\\htmlData{anchor=rise-silver}{\\Delta T_{\\mathrm{silver}}}=T_{\\mathrm{final,silver}}-T_{\\mathrm{initial,silver}}"},{"text":"The tube with the larger temperature rise absorbed more thermal radiation, so its surface is the better absorber. This explanation earns A1."}],"highlights":[{"color":"orange","style":"box","anchor":"rise-black"},{"color":"sky","style":"box","anchor":"rise-silver"}]},"order":3,"title":"Compare temperature increases","description":"For each tube, calculate how much its water temperature changed over the same heating time."}]}],"generatedAt":"2026-07-22T09:14:47.004Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"1d626d4b-07df-401e-a5c7-7d157ee42ebd","revisionId":"20cdfa72-6740-4441-bb70-026fdc432135","questionNumber":null,"questionType":"LA","specification":"Figure 1 shows some apparatus.\n\n![Apparatus for thermal radiation investigation](https://assets.mathsgenie.co.uk/aqa-qb/bc86b2ac-a821-4e0f-bc70-f632122bd491.png)","difficulty":5,"difficultyBand":"medium","totalMarks":6,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"da8341ba-b782-4aaf-98ea-c23af6430bc4","label":null,"content":"Describe an investigation to find out how the nature of a surface affects the rate at which it emits thermal radiation.\n\nYou should use the apparatus shown in Figure 1 and any additional standard laboratory equipment you need.","markscheme":"- Describes placing the Leslie's cube on a heatproof mat and carefully filling it with boiling/hot water from the kettle B1\n- States that the distance between the infrared detector and the face of the cube must be kept constant (using the wooden ruler) for all measurements M1\n- Aligns the detector perpendicular to one of the vertical faces (e.g. matte black, matte white, shiny silver) M1\n- Records the detector's output (voltage/reading on the multimeter) for that face A1\n- Repeats the measurement for each of the other vertical faces at the same distance and as quickly as possible (before the water cools significantly) M1\n- Concludes that the surface with the highest reading (matte black) is the best emitter of thermal radiation, and the one with the lowest reading (shiny silver) is the poorest emitter A1","marks":6,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"compare_emission","label":"Compare detector readings","steps":[{"type":"text","order":0,"title":"Prepare the cube","content":"Place Leslie’s cube on the heatproof mat. Carefully fill it with hot or boiling water from the kettle, taking care because the water and cube will be hot.\n\nThis gives all the vertical faces the same hot source, so any difference in detector reading can be attributed to the nature of the surface. **This earns B1.**","highlights":[{"text":"You should use the apparatus shown in Figure 1 and any additional standard laboratory equipment you need.","location":"specification"}]},{"type":"text","order":1,"title":"Control the distance","content":"Use the wood

Thermal radiation and energy balance

Question 4

Thermal radiation and energy balance Questions

Thermal radiation and energy balance

Question 4

Thermal radiation and energy balance Questions