Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
Refraction and Refractive Index — exam questions
11 original Incandio exam-style questions on Refraction and Refractive Index, 27 marks, about 27 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Refraction and Refractive Index — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
8 command words run through this set, and on Pearson Edexcel International GCSE Physics each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- State (1 mark)
- one precise fact or definition
- Which (1 mark)
- one option chosen from the set given
- Explain (2–4 marks)
- the physics that causes it, set out as a line of reasoning Misread as: describing the change without giving the physical reason for it
- Calculate (1–5 marks)
- select the equation, substitute, evaluate — and state the unit Misread as: giving a bare number with no equation and no unit
- Determine (1–4 marks)
- a value obtained by combining a reading or gradient with a relationship
- Describe (2–4 marks)
- developed, linked statements of what happens — including a named direction where one exists
- Suggest (1–3 marks)
- a plausible answer applying taught physics to an unfamiliar arrangement
- Give (1–2 marks)
- a short factual answer
Assessed on Paper 1 (4PH1/1P) and Paper 2 (4PH1/2P), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Physics (4PH1) — statements 3.17 · 3.18 · 3.19. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 11 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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A student directs a narrow ray of light at one face of a rectangular glass block and marks the path of the ray entering and leaving with pencil crosses. She draws round the block, removes it, joins the crosses, and measures the angle of incidence and the angle of refraction at the first face. She repeats this for five different angles.
Table 1 — the student's measurements at the first face Angle of incidence / ° Angle of refraction / ° sin i sin r 20 13.2 0.342 0.228 30 19.5 0.500 0.334 40 25.4 0.643 0.429 50 30.7 0.766 0.511 60 35.3 0.866 0.578 (a)
(1)Give
Give the angle of refraction recorded for an angle of incidence of 40°, using Table 1.
A student directs a narrow ray of light at one face of a rectangular glass block and marks the path of the ray entering and leaving with pencil crosses. She draws round the block, removes it, joins the crosses, and measures the angle of incidence and the angle of refraction at the first face. She repeats this for five different angles.
Table 1 — the student's measurements at the first face Angle of incidence / ° Angle of refraction / ° sin i sin r 20 13.2 0.342 0.228 30 19.5 0.500 0.334 40 25.4 0.643 0.429 50 30.7 0.766 0.511 60 35.3 0.866 0.578 angle of refraction recorded = ............................ °
(b)
(2)Calculate
Calculate the refractive index of the glass from the 60° row of Table 1.
A student directs a narrow ray of light at one face of a rectangular glass block and marks the path of the ray entering and leaving with pencil crosses. She draws round the block, removes it, joins the crosses, and measures the angle of incidence and the angle of refraction at the first face. She repeats this for five different angles.
Table 1 — the student's measurements at the first face Angle of incidence / ° Angle of refraction / ° sin i sin r 20 13.2 0.342 0.228 30 19.5 0.500 0.334 40 25.4 0.643 0.429 50 30.7 0.766 0.511 60 35.3 0.866 0.578 refractive index of the glass = ............................
(c)
(3)Explain
Explain what Table 1 shows about the refractive index of this glass at different angles.
A student directs a narrow ray of light at one face of a rectangular glass block and marks the path of the ray entering and leaving with pencil crosses. She draws round the block, removes it, joins the crosses, and measures the angle of incidence and the angle of refraction at the first face. She repeats this for five different angles.
Table 1 — the student's measurements at the first face Angle of incidence / ° Angle of refraction / ° sin i sin r 20 13.2 0.342 0.228 30 19.5 0.500 0.334 40 25.4 0.643 0.429 50 30.7 0.766 0.511 60 35.3 0.866 0.578 (d)
(3)Suggest
Suggest why the student used angles of incidence spread from 20° to 60° rather than five angles between 20° and 25°.
A student directs a narrow ray of light at one face of a rectangular glass block and marks the path of the ray entering and leaving with pencil crosses. She draws round the block, removes it, joins the crosses, and measures the angle of incidence and the angle of refraction at the first face. She repeats this for five different angles.
Table 1 — the student's measurements at the first face Angle of incidence / ° Angle of refraction / ° sin i sin r 20 13.2 0.342 0.228 30 19.5 0.500 0.334 40 25.4 0.643 0.429 50 30.7 0.766 0.511 60 35.3 0.866 0.578 (Total for Question 1 = 9 marks)
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(1)State
State what happens to the direction of a ray of light as it passes from air into glass at an angle to the normal.
(Total for Question 2 = 1 mark)
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(1)Which
Which expression gives the refractive index of a material?
Expression A sin r ÷ sin i B sin i ÷ sin r C sin i × sin r D i ÷ r (Total for Question 3 = 1 mark)
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(3)Explain
Explain why a ray of light changes direction when it enters a glass block at an angle.
Figure 1 — a ray meeting a boundary (Total for Question 4 = 3 marks)
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(3)Calculate
A ray enters a transparent plastic at an angle of incidence of 45°. The angle of refraction is 28°. Calculate the refractive index of the plastic.
refractive index of the plastic = ............................
(Total for Question 5 = 3 marks)
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(3)Determine
Light strikes a water surface with an angle of incidence of 50°. The refractive index of water is 1.33. Determine the angle of refraction.
angle of refraction = ............................ °
(Total for Question 6 = 3 marks)
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(4)Describe
Describe how a student could use a rectangular glass block, a ray box and a protractor to find the refractive index of the glass.
(Total for Question 7 = 4 marks)
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(3)Suggest
Suggest why the blue light is deviated more than the red light.
White light through a prism — White light entering a glass prism emerges spread into a band of colours. Measurements on one prism give a refractive index of 1.513 for red light and 1.532 for blue light. Both colours enter at the same angle of incidence.
(Total for Question 8 = 3 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 11 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Refraction and Refractive Index to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Ibn al-Haytham over three rounds, marked against descriptors you can read first.
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Back to the lesson
- Refraction and Refractive Index — Why light bends entering glass, why it sometimes does not, and how to put a number on it.
- All of Incandio Physics · Incandio Exam Practice