Official June 2024 AQA A-level PHYSICS 7408/3BB Paper 3 Section B Medical physics Merged Question Paper + Mark Scheme + Insert Ace your Mocks!!! *JUN2474083bB01* IB/M/Jun24/E8 7408/3BB For Examiner’s Use Question Mark 1 2 3 4 5 TOTAL Monday 17 June 2024 Morning Materials For this paper you must have: • a pencil and a ruler • a scientific calculator • a Data and Formulae Booklet • a protractor. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • Do all rough work in this book. Cross through any work you do not want to be marked. • Show all your working. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 35. • You are expected to use a scientific calculator where appropriate. • A Data and Formulae Booklet is provided as a loose insert. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. A-level PHYSICS Paper 3 Section B Medical physics Time allowed: The total time for both sections of this paper is 2 hours. You are advised to spend approximately 50 minutes on this section. 2 *02* IB/M/Jun24/7408/3BB Do not write outside the Section B box Answer all questions in this section. 0 1 . 1 A human eye has a far point of 6.0 m. State the name of this defect of vision. [1 mark] 0 1 . 2 Calculate the power of the correcting lens required for this eye. [2 marks] power = D 0 1 . 3 An eye with astigmatism requires the following prescription: −4.00 –0.75 ×30 Which row identifies the meaning of each number? Tick () one box. [1 mark] −4.00 −0.75 ×30 axis cylinder spherical cylinder axis spherical spherical cylinder axis cylinder spherical axis 4 3 *03* Turn over ► IB/M/Jun24/7408/3BB Do not write outside the 0 2 box . 1 A stadium is full of spectators. The peak sound-intensity level at the centre of the stadium is 110 dB. On another occasion the number of spectators in the stadium is reduced by 60%. Estimate the peak sound-intensity level at the centre of the stadium. You should assume that on both occasions: • the sound intensity produced by each spectator is the same • the spectators are distributed evenly around the stadium. [4 marks] peak sound-intensity level = dB 0 2 . 2 Describe the changes to a person’s hearing that may result from prolonged exposure to sound at 110 dB. [2 marks] 6 4 *04* IB/M/Jun24/7408/3BB Do not write outside the 0 3 box . 1 Name the two types of optical fibre bundle used in an endoscope. Go on to discuss whether the optical fibres in either of these bundles require cladding. [4 marks] 0 3 . 2 Modal and material dispersion can cause problems in fibre-optic communications. Discuss why the methods used to reduce modal and material dispersion are not required in an endoscope. In your answer you should: • describe the methods used to reduce dispersion in an optical fibre used for communication • explain why the methods are not required in an endoscope • explain how using these methods in an endoscope would affect its function. [6 marks]