AQA GCSE Computer Science Paper 2: Computing concepts June 2023 question paper 8525/2

The number base 2 is called binary.

Shade one lozenge to show which number base is called hexadecimal.

Shade two lozenges to show the statements that are true about hexadecimal.

Convert the decimal number 171 into binary.

Convert the hexadecimal number 2D into binary.

You should show your working.

Convert 16 000 000 bits to megabytes (MB).

You should show your working.

Describe the binary shift that would be used to divide a binary number by four.

When a sound wave is converted to a digital form it is sampled. The sampling rate is measured in hertz (Hz).

Define the term hertz.

A sampling rate of 20 000 Hz and a sample resolution of four bits is used to make a digital recording of a sound that lasts 50 seconds.

What is the minimum file size of the recording in megabytes (MB)?

You should show your working.

The term pixel is short for Picture Element.

Define the term pixel.

Figure 1 shows a 5 pixel x 5 pixel image. A minimum colour depth of two bits is needed to store the image.

Explain how the image in Figure 1 can be represented as a bitmap.

A 10 pixel x 10 pixel image contains five different colours.

Calculate the minimum file size, in bits, of this image when represented as a bitmap.

You should show your working.

bits

A black and white image has been compressed using run length encoding (RLE).

The first bit in each byte of the bit pattern represents the colour and the remaining seven bits of the byte represent the number of pixels in the run.

The image has a run of 60 black pixels followed by a run of 30 white pixels and is represented by the bit pattern shown in Figure 2.

Using the same RLE method, give the bit pattern for a black and white image that has a run of 64 white pixels followed by a run of 15 black pixels.

Write your answer in Table 1.

Define the term hardware.

Describe the role of each of the following components of a CPU:

Clock

Control unit

Give one reason why a CPU with two cores might perform faster than an equivalent CPU with only one core.

Define the term non-volatile memory.

Give one example of a type of volatile memory in a computer system.

Explain why secondary storage is required in a computer system.

Define the term software.

Define the term system software.

Define the term application software.

Explain the role of main memory in the execute stage of the Fetch-Execute cycle.

Describe the other two stages of the Fetch-Execute cycle.

Fetch stage

Decode stage

Complete the truth table for the XOR logic gate.

Figure 3 shows a logic circuit.

State the type of logic gate labelled G₁ in Figure 3.

Write a Boolean expression to show how the output D is calculated from the inputs A, B and C in Figure 3.

You must use the correct symbols for the Boolean operators in your expression.

Figure 4 shows three programs (A, B, C) that add two numbers and output the result. The programs are written in different programming languages.

Identify the type of programming language used for each program shown in Figure 4 by writing A, B or C in the correct row of Table 2.

You must only use each letter once.

State one advantage of writing programs in assembly language instead of a high-level language.

Shade one lozenge to show which statement is true about program translators.

Describe two differences between a PAN and a WAN.

Difference 1

Difference 2

Shade two lozenges to show which statements are true about LANs.

State two differences between a bus topology and a star topology.

Difference 1

Difference 2

HTTP is an example of a network protocol.

Define the term network protocol.

The application layer and the transport layer are two of the layers within the TCP/IP model.

What are the names of the other two layers of the TCP/IP model?

A teacher keeps a record of books loaned to students.

The teacher uses a relational database containing three tables, BookCopy, Student and Loan. Figure 5 shows some data from the tables.

Shade two lozenges to show which of the following statements are benefits of relational databases.

State one field in the Loan table that is a foreign key.

State the most suitable data type for the DepositPaid field in the Loan table.

Figure 5 has been included again below.

Year 11 students must return their books after they have finished their GCSE exams.

Using the database shown in Figure 5, write an SQL query that lists all the loans for students who are in Year 11.

The query must only return:

• both names of the student

• the ID of the book borrowed

• the deposit paid.

The results must be in ascending order of the students’ last names.

Barry Tucker has returned their copy of the book Python Basics.

Complete the SQL to delete the loan record for the book PB002.

DELETE FROM

WHERE

Wearable devices, such as smartwatches and fitness trackers, have become more popular in recent years. This has led to an increase in the amount of personal, health-related data being collected by technology companies.

Discuss the:

• benefits of collecting personal, health-related data using wearable devices

• data privacy issues related to the collection of personal, health-related data

• legal issues related to the collection of personal, health-related data.

Define the term cyber security.

State one type of malware.

The network manager of a new computer games company, AQAware, is configuring the network. They are concerned about potential cyber security threats that could affect the company’s systems.

Discuss the potential impact of the following threats on AQAware:

• weak and default passwords

• misconfigured access rights

• unpatched and/or outdated software.

In your response you should include:

• how these threats could be exploited by an attacker

• how AQAware could protect themselves against these threats.