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*JUN25 74083 BD01*
IB/M/Jun25/G4006/E7 7408/3BD
For Examiner’s Use Question Mark 1 2 3 4 TOTAL
Tuesday 17 June 2025 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 Turning points in physics
Time allowed: The total time for
both sections of this paper is
- hours. You are advised to
spend approximately 50 minutes on this section. 1 / 3
2
*02* IB/M/Jun25/7408/3BD
Do not write outside the box Section B
Answer all questions in this section.
- 1
This question is about Thomson’s determination of the electron’s specific charge.
You should not use the values of the electron charge, mass or specific charge from the data and formulae booklet in this question.
Figure 1 shows part of the apparatus that Thomson used to measure the specific charge of the electron.
Figure 1
- 1
. 1 A modern version of Thomson’s apparatus uses thermionic emission in the production of the electron beam.
Suggest how the electron beam is produced in this modern version.You should include a labelled diagram and suitable values for the power supplies used.[3 marks]
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3
*03* Turn over ►
IB/M/Jun25/7408/3BD
Do not write outside the box
Question 1 continues on the next page
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