MERGED QUESTION PAPER> MARK SCHEME> 100% GUARANTEE
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signatu re
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.
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=
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 ►
IB/M/Jun24/7408/3BE
, 4
Do not write
outside the
0 1 . 4 Figure 4 shows a generalised layout of an integrated circuit (IC) for an N-bit binary box
counter.
Q0 is the output that provides the least significant bit.
Figure 4
A signal generator feeds a square wave of frequency 1024 Hz into the clock of the IC.
The N-bit binary counter generates the 512 Hz signal and the 1 Hz signal from
separate outputs.
Deduce which of the outputs Q0 to QN will provide the 1 Hz signal.
[1 mark]
IB/M/Jun24/7408/3BE
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signatu re
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.
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=
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 ►
IB/M/Jun24/7408/3BE
, 4
Do not write
outside the
0 1 . 4 Figure 4 shows a generalised layout of an integrated circuit (IC) for an N-bit binary box
counter.
Q0 is the output that provides the least significant bit.
Figure 4
A signal generator feeds a square wave of frequency 1024 Hz into the clock of the IC.
The N-bit binary counter generates the 512 Hz signal and the 1 Hz signal from
separate outputs.
Deduce which of the outputs Q0 to QN will provide the 1 Hz signal.
[1 mark]
IB/M/Jun24/7408/3BE
