pectrum: red, orange, yellow, green, blue, indigo, and violet.\n\nA beam of white light passes through a transparent filter **X**.\nFilter **X** absorbs blue, indigo, and violet light.","difficulty":4,"difficultyBand":"medium","totalMarks":7,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"885da785-ff5e-495e-9da4-4a1ed84e3aaf","label":"a","content":"What colours of light are transmitted by filter **X**?","markscheme":"- Identifies that the transmitted colours are red, orange, yellow, and green B1","marks":1,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"identify_transmitted_colours","label":"Identify transmitted colours","steps":[{"type":"text","order":0,"title":"Use the absorption information","content":"A filter transmits the colours it does **not** absorb. The question says filter $X$ absorbs blue, indigo, and violet, so remove those three colours from the visible spectrum.","highlights":[{"text":"Filter **X** absorbs blue, indigo, and violet light.","location":"specification"}]},{"type":"text","order":1,"title":"State the transmitted colours","content":"The remaining colours are **red, orange, yellow, and green**. These are the colours transmitted by filter $X$, earning the B1 mark.","highlights":[{"text":"What colours of light are transmitted by filter **X**?","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:45:11.988Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"18c532c5-5652-43a0-9ca2-ddddcf415086","label":"b","content":"The light that leaves filter **X** then passes through another transparent filter **Y**. The light that leaves filter **Y** is orange light. What colours of light are absorbed by filter **Y**?","markscheme":"- Identifies that the light entering filter **Y** consists of red, orange, yellow, and green M1\n- Deduces that filter **Y** must absorb red, yellow, and green light A1","marks":2,"order":1,"markingRubric":null,"explanation":{"methods":[{"id":"track_colours","label":"Track the colours","steps":[{"type":"text","order":0,"title":"Track colours into Y","content":"Filter **X** absorbs blue, indigo, and violet light, so those three colours are removed from the white light. The colours left to enter filter $Y$ are red, orange, yellow and green. This identifies the light entering $Y$, earning **M1**.","highlights":[{"text":"Filter **X** absorbs blue, indigo, and violet light.","location":"specification"}]},{"type":"text","order":3,"title":"Deduce Y absorption","content":"The light leaving filter **Y** is orange only. Therefore, filter $Y$ must absorb the other colours that enter it: red, yellow and green. This earns **A1**.","highlights":[{"text":"The light that leaves filter **Y** is orange light.","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:50:42.267Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"b27b13b4-919b-4dd1-8e9b-bf44f42f4ef1","label":"c","content":"A stage costume is dyed red.\n\nWhen certain coloured spotlights shine on it, the red costume appears black. Explain why this occurs in terms of reflection and absorption.","markscheme":"- Explains that the red costume only reflects red light and absorbs all other wavelengths/colours of light M1\n- Explains that if the spotlight contains no red light, all incident light is absorbed, no light is reflected, and the costume appears black A1","marks":2,"order":2,"markingRubric":null,"explanation":{"methods":[{"id":"reflection_absorption","label":"Reflection and absorption","steps":[{"type":"text","order":1,"title":"Recall the colour rule","content":"In white light, a coloured object appears that colour because it reflects that colour into your eyes.\n\nA red costume reflects red light and absorbs all other colours (wavelengths) of light. This earns **M1**.","highlights":[{"text":"A stage costume is dyed red.","location":"specification"}]},{"type":"text","order":2,"title":"Consider the spotlight","content":"For the costume to look bla

Wave interactions

Question 8

Wave interactions Questions

Wave interactions

Question 8

Wave interactions Questions