Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
PHYSICS
Paper 1
Wednesday 14 May 2025 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a pencil and a ruler
Question Mark
• a scientific calculator
• a Data and Formulae Booklet 1
• a protractor. 2
3
Instructions
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page. 5
• Answer all questions. 6
• You must answer the questions in the spaces provided. Do not write
7
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 TOTAL
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 70.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 Hydrogen has three naturally occurring isotopes. One of these isotopes is
( )
hydrogen-3 13H .
0 1 . 1 Calculate the specific charge of a nucleus of hydrogen-3.
[2 marks]
specific charge = ________________________ C kg−1
0 1 . 2 The specific charge of the hydrogen-3 nucleus is less than the specific charges of the
nuclei of the other two isotopes.
Suggest why.
[2 marks]
IB/M/Jun25/7407/1
, 3
Do not write
outside the
Kaons (K) and pions (π) are produced when a beam of antiprotons is incident on a box
sample of hydrogen gas.
One reaction that occurs is
p + p → K− + π+ + K0
0 1 . 3 Deduce, with reference to appropriate conservation laws, the quark structure of the
K0 produced in this reaction.
[3 marks]
quark structure =
0 1 . 4 One possible decay of a π+ particle is
π+ → A + B
where A is a charged lepton.
Suggest, with reference to appropriate conservation laws, the name of A and the
name of B.
[2 marks]
name of A
name of B 9
Turn over ►
IB/M/Jun25/7407/1
, 4
Do not write
outside the
0 2 An optical fibre consists of a glass core surrounded by cladding. box
Monochromatic light enters the glass core of the optical fibre from air.
0 2 . 1 What happens to the frequency of the light as it enters the glass core?
Tick (✓) one box.
[1 mark]
It decreases.
It is unchanged.
It increases.
The refractive index of the glass core is 1.51
0 2 . 2 The critical angle at the core–cladding boundary is 80.7°
Calculate the refractive index of the cladding.
[2 marks]
refractive index of cladding =
IB/M/Jun25/7407/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
PHYSICS
Paper 1
Wednesday 14 May 2025 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a pencil and a ruler
Question Mark
• a scientific calculator
• a Data and Formulae Booklet 1
• a protractor. 2
3
Instructions
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page. 5
• Answer all questions. 6
• You must answer the questions in the spaces provided. Do not write
7
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 TOTAL
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 70.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 Hydrogen has three naturally occurring isotopes. One of these isotopes is
( )
hydrogen-3 13H .
0 1 . 1 Calculate the specific charge of a nucleus of hydrogen-3.
[2 marks]
specific charge = ________________________ C kg−1
0 1 . 2 The specific charge of the hydrogen-3 nucleus is less than the specific charges of the
nuclei of the other two isotopes.
Suggest why.
[2 marks]
IB/M/Jun25/7407/1
, 3
Do not write
outside the
Kaons (K) and pions (π) are produced when a beam of antiprotons is incident on a box
sample of hydrogen gas.
One reaction that occurs is
p + p → K− + π+ + K0
0 1 . 3 Deduce, with reference to appropriate conservation laws, the quark structure of the
K0 produced in this reaction.
[3 marks]
quark structure =
0 1 . 4 One possible decay of a π+ particle is
π+ → A + B
where A is a charged lepton.
Suggest, with reference to appropriate conservation laws, the name of A and the
name of B.
[2 marks]
name of A
name of B 9
Turn over ►
IB/M/Jun25/7407/1
, 4
Do not write
outside the
0 2 An optical fibre consists of a glass core surrounded by cladding. box
Monochromatic light enters the glass core of the optical fibre from air.
0 2 . 1 What happens to the frequency of the light as it enters the glass core?
Tick (✓) one box.
[1 mark]
It decreases.
It is unchanged.
It increases.
The refractive index of the glass core is 1.51
0 2 . 2 The critical angle at the core–cladding boundary is 80.7°
Calculate the refractive index of the cladding.
[2 marks]
refractive index of cladding =
IB/M/Jun25/7407/1
