AQA AS COMPUTER SCIENCE PPER 2 QP 2020
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
COMPUTER SCIENCE
Paper 2
Friday 22 May 2020 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have:
• a calculator. For Examiner’s Use
Instructions Question Mark
• Use black ink or black ball-point pen. 1
• Fill in the boxes at the top of this page.
2
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write outside 3
the box around each page or on blank pages. 4
• If you need extra space for your answer(s), use the lined pages at the end of 5
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 6
be marked. 7
8
Information
9
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 75. 10
TOTAL
Advice
• In some questions you are required to indicate your answer by completely
shading a lozenge alongside the appropriate answer as shown.
• If you want to change your answer you must cross out your original answer as
shown.
• If you wish to return to an answer previously crossed out, ring the answer you
now wish to select as shown.
*JUN207516201*
IB/G/Jun20/E16 7516/2
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 State the decimal equivalent of the hexadecimal number C57
[1 mark]
0 1 . 2 How many different values can be represented using two bytes?
[1 mark]
0 1 . 3 A data transmission system transmits one byte of data, using the majority voting
system for error correction.
Figure 1 shows the bit pattern that was received.
Figure 1
1 1 1 0 0 0 0 0 0 1 1 0 0 0 1 1 0 1 1 1 1 0 1 1
Shade one lozenge to indicate the byte of data that the receiver will assume was
sent.
[1 mark]
A 10010011
B 10011011
C 10010111
D 10011110
*02*
IB/G/Jun20/7516/2
, 3
Do not write
outside the
0 1 . 4 A check digit can be used to detect errors when data are entered or transmitted. box
Explain what a check digit is and outline how the check digit is generated.
[2 marks]
5
0 2 . 1 Figure 2 shows two unsigned binary integers.
Figure 2
0 0 1 0 1 1 0 1
0 0 0 0 0 1 0 1
What is the result in binary of multiplying the two numbers shown in Figure 2?
You must show all your working in binary.
[2 marks]
Answer
Question 2 continues on the next page
Turn over ►
*03*
IB/G/Jun20/7516/2
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
COMPUTER SCIENCE
Paper 2
Friday 22 May 2020 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have:
• a calculator. For Examiner’s Use
Instructions Question Mark
• Use black ink or black ball-point pen. 1
• Fill in the boxes at the top of this page.
2
• Answer all questions.
• You must answer the questions in the spaces provided. Do not write outside 3
the box around each page or on blank pages. 4
• If you need extra space for your answer(s), use the lined pages at the end of 5
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 6
be marked. 7
8
Information
9
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 75. 10
TOTAL
Advice
• In some questions you are required to indicate your answer by completely
shading a lozenge alongside the appropriate answer as shown.
• If you want to change your answer you must cross out your original answer as
shown.
• If you wish to return to an answer previously crossed out, ring the answer you
now wish to select as shown.
*JUN207516201*
IB/G/Jun20/E16 7516/2
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 State the decimal equivalent of the hexadecimal number C57
[1 mark]
0 1 . 2 How many different values can be represented using two bytes?
[1 mark]
0 1 . 3 A data transmission system transmits one byte of data, using the majority voting
system for error correction.
Figure 1 shows the bit pattern that was received.
Figure 1
1 1 1 0 0 0 0 0 0 1 1 0 0 0 1 1 0 1 1 1 1 0 1 1
Shade one lozenge to indicate the byte of data that the receiver will assume was
sent.
[1 mark]
A 10010011
B 10011011
C 10010111
D 10011110
*02*
IB/G/Jun20/7516/2
, 3
Do not write
outside the
0 1 . 4 A check digit can be used to detect errors when data are entered or transmitted. box
Explain what a check digit is and outline how the check digit is generated.
[2 marks]
5
0 2 . 1 Figure 2 shows two unsigned binary integers.
Figure 2
0 0 1 0 1 1 0 1
0 0 0 0 0 1 0 1
What is the result in binary of multiplying the two numbers shown in Figure 2?
You must show all your working in binary.
[2 marks]
Answer
Question 2 continues on the next page
Turn over ►
*03*
IB/G/Jun20/7516/2
