Fig. 1.1.","markscheme":"- Refracted ray drawn inside the glass block starting from the entry point and bending towards the normal (the angle of refraction is smaller than the angle of incidence) M1","marks":1,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"refraction_rule","label":"Use the normal","steps":[{"type":"text","order":0,"title":"Use the normal","content":"Identify the dashed line as the normal. As the ray enters the crown glass from air, it bends towards this line.","highlights":[{"text":"entering a rectangular block of crown glass from the air","location":"specification"}]},{"type":"text","order":1,"title":"Draw the refracted ray","content":"Starting at the entry point, draw a straight ray inside the glass **closer to the normal** than the incident ray, so the angle of refraction is smaller. Add an arrowhead pointing into the block.\n\nThis earns the **M1** mark: the ray starts at the entry point and bends towards the normal.","highlights":[{"text":"Draw the path of the refracted ray inside the crown glass block in Fig. 1.1.","location":"specification"},{"text":"When the green light enters the glass block from the air it will refract.","location":"specification"}]}]}],"generatedAt":"2026-07-22T12:14:43.531Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"4375e848-789b-452b-9c75-770ded5d4a89","label":"b","content":"Explain why green light refracts as it enters the glass block.","markscheme":"- Crown glass is more optically dense (or has a higher refractive index) than air B1\n- This causes the speed of the green light to decrease (slow down) upon entering the glass, causing a change in direction B1","marks":2,"order":1,"markingRubric":null,"explanation":{"methods":[{"id":"optical_density","label":"Link density to speed","steps":[{"type":"text","order":0,"title":"Compare the materials","content":"Crown glass is more optically dense than air (it has a higher refractive index).\n\nThis comparison earns **B1**.","highlights":[{"text":"entering a rectangular block of crown glass from the air","location":"specification"}]},{"type":"text","order":1,"title":"Explain the direction change","content":"As the green light enters the more optically dense crown glass, its speed decreases. This decrease in speed causes the ray to change direction: this is refraction.\n\nStating that it slows down and changes direction earns **B1**.","highlights":[{"text":"When the green light enters the glass block from the air it will refract.","location":"specification"}]}]}],"generatedAt":"2026-07-22T12:16:20.289Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"6ae3b7bc-27a7-4f36-af4a-04d3fb3211ac","label":"c","content":"A student uses the green laser and the glass block to investigate the relationship between the angle of incidence and angle of refraction for this type of glass.\n\nThe table shows the student's results.\n\n| Angle of incidence (\\(^{\\circ}\\)) | Angle of refraction (\\(^{\\circ}\\)) |\n| :---: | :---: |\n| 15 | 10 |\n| 35 | 22 |\n| 55 | 33 |\n| 75 | 40 |\n\nDescribe a method the student could have used to investigate this relationship.","markscheme":"- Trace the outline of the glass block on paper and draw a normal line perpendicular to the boundary at the point of incidence M1\n- Use a protractor to mark the specified angles of incidence (15°, 35°, 55°, 75°) M1\n- Shine the laser along these directions, mark the entry and exit points, then join them to trace the path inside the block M1\n- Use a protractor to measure the corresponding angles of refraction (between the path inside the block and the normal) A1","marks":4,"order":2,"markingRubric":null,"explanation":{"methods":[{"id":"ray_tracing","label":"Ray tracing practical","steps":[{"type":"text","order":0,"title":"Prepare the outline","content":"Place the glass block on plain paper and trace around it. At the point where the laser will enter, draw a **norma

Wave behaviour

Question 36

Wave behaviour Questions

Wave behaviour

Question 36

Wave behaviour Questions