VERIFIED 2024 JUNE
AQA
A-level
PHYSICS
7408/3BE
Paper 3 Section B Electronics
100% GUARANTEE
MERGED QUESTION PAPER> MARK SCHEME> INSERT
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, 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 Electronics
Monday 17 June 2024 Morning Time allowed: The total time for
Materials
both sections of this paper is
For this paper you must have: 2 hours. You are advised to
• a pencil and a ruler spend approximately
• a scientific calculator
• a Data and Formulae Booklet 50 minutes on this section.
• a protractor.
For Examiner’s Use
Instructions
• Use black ink or black ball-point pen. Question Mark
• Fill in the boxes at the top of this page. 1
• Answer all questions.
2
• You must answer the questions in the spaces provided. Do not write
outside the box around each page or on blank pages. 3
• If you need extra space for your answer(s), use the lined pages at the end of 4
this book. Write the question number against your answer(s). 5
• Do all rough work in this book. Cross through any work you do not want
to be marked. TOTAL
• 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.
*JUN2474083BE01*
IB/M/Jun24/E8 7408/3BE
, 2
Do not write
outside the
Section B box
Answer all questions in this section.
0 1 A toy manufacturer is designing a two-tone siren for use in small battery-operated
cars.
Figure 1 shows design Option 1.
Option 1 uses three separate signal generators feeding into a logic sub-system.
The signal generators produce logic-compatible 9 V square waves of frequencies
1024 Hz, 1 Hz and 512 Hz.
Figure 1
The waveforms shown are not to scale.
0 1 . 1 Explain how the logic level applied at B in Figure 1 determines the output frequency
at Q.
[2 marks]
0 1 . 2 Write the Boolean algebra expression for output Q in terms of the inputs A, B and C.
Use only the logic operations shown in Figure 1.
[2 marks]
Q=
*02*
IB/M/Jun24/7408/3BE
, 3
Do not write
outside the
0 1 . 3 Option 1 is tested by replacing the 1 Hz signal generator with a manual input. box
The manual input is provided by the combination of a push-to-make switch
and a 10 kΩ resistor.
The combination produces the following voltages at its output:
• 0 V when the switch is not pressed
• 9 V when the switch is pressed.
Figure 2 shows the symbol for the push-to-make switch.
Figure 2
Complete Figure 3 to show how this switch and the 10 kΩ resistor are connected.
Label the output Vout.
You do not need to add details taken from Figure 1.
[1 mark]
Figure 3
Question 1 continues on the next page
Turn over ►
*03*
IB/M/Jun24/7408/3BE
AQA
A-level
PHYSICS
7408/3BE
Paper 3 Section B Electronics
100% GUARANTEE
MERGED QUESTION PAPER> MARK SCHEME> INSERT
SCROLL DOWN
, 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 Electronics
Monday 17 June 2024 Morning Time allowed: The total time for
Materials
both sections of this paper is
For this paper you must have: 2 hours. You are advised to
• a pencil and a ruler spend approximately
• a scientific calculator
• a Data and Formulae Booklet 50 minutes on this section.
• a protractor.
For Examiner’s Use
Instructions
• Use black ink or black ball-point pen. Question Mark
• Fill in the boxes at the top of this page. 1
• Answer all questions.
2
• You must answer the questions in the spaces provided. Do not write
outside the box around each page or on blank pages. 3
• If you need extra space for your answer(s), use the lined pages at the end of 4
this book. Write the question number against your answer(s). 5
• Do all rough work in this book. Cross through any work you do not want
to be marked. TOTAL
• 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.
*JUN2474083BE01*
IB/M/Jun24/E8 7408/3BE
, 2
Do not write
outside the
Section B box
Answer all questions in this section.
0 1 A toy manufacturer is designing a two-tone siren for use in small battery-operated
cars.
Figure 1 shows design Option 1.
Option 1 uses three separate signal generators feeding into a logic sub-system.
The signal generators produce logic-compatible 9 V square waves of frequencies
1024 Hz, 1 Hz and 512 Hz.
Figure 1
The waveforms shown are not to scale.
0 1 . 1 Explain how the logic level applied at B in Figure 1 determines the output frequency
at Q.
[2 marks]
0 1 . 2 Write the Boolean algebra expression for output Q in terms of the inputs A, B and C.
Use only the logic operations shown in Figure 1.
[2 marks]
Q=
*02*
IB/M/Jun24/7408/3BE
, 3
Do not write
outside the
0 1 . 3 Option 1 is tested by replacing the 1 Hz signal generator with a manual input. box
The manual input is provided by the combination of a push-to-make switch
and a 10 kΩ resistor.
The combination produces the following voltages at its output:
• 0 V when the switch is not pressed
• 9 V when the switch is pressed.
Figure 2 shows the symbol for the push-to-make switch.
Figure 2
Complete Figure 3 to show how this switch and the 10 kΩ resistor are connected.
Label the output Vout.
You do not need to add details taken from Figure 1.
[1 mark]
Figure 3
Question 1 continues on the next page
Turn over ►
*03*
IB/M/Jun24/7408/3BE
