GCSE COMPUTER SCIENCE — Actual May 2025 PAST PAPER: Computer Systems
All Assessment Questions & Mark Scheme [OCR J277/01]
Exam Resource Summary
The GCSE (9–1) Computer Science May 2025 Computer Systems Paper (OCR J277/01) merges the
full official examination paper with its detailed mark scheme to provide a clear and structured
revision resource. This paper assesses students’ understanding of key computer science concepts,
including hardware, software, networks, data representation, and system security. Candidates are
required to apply theoretical knowledge to problem-solving scenarios, interpret technical
information, and demonstrate logical reasoning and computational thinking. By presenting each
question alongside its marking criteria, the resource clarifies examiner expectations, highlights the
analytical and problem-solving skills required for high-band responses, and guides learners in
producing precise, well-structured answers. This integrated format supports focused revision,
reinforces core computer science principles, and prepares students thoroughly for the 2026 OCR
GCSE Computer Science Computer Systems examination.
OCR is an exempt Charity
Turn over
, 2
1 A student is creating a presentation containing images and sound.
(a) One of the files is an audio recording.
Complete the description of how a computer stores sound. Fill in the gaps using the given list of
terms. Not all terms will be used.
analogue colour depth higher repeated smaller
binary digital lower sample rate unique
bit depth height measuring sampling
byte hertz recording seconds
An .....................................................................sound wave needs to be converted into a digital
sound wave.
Sound .................................................................... is when the amplitude of the sound wave is
measured at set intervals.
The..................................................................... is the number of times a second the sound wave
is measured. This is given in Hertz.
Each amplitude is given a..................................................................... binary number. The
number of bits allocated to each sample is the ..................................................................... .
The..................................................................... the number of bits, the wider the number of
amplitudes can be measured.
[6]
© OCR 2025
, 3
(b) The student creates 10 bitmap images using a computer.
Each image has a colour depth of 8-bits and a resolution of 800 × 500 pixels.
(i) Define the term pixel.
..........................................................................................................................................................
. ................................................................................................................................................. [1]
(ii) Calculate the total file size of the 10 images in kilobytes.
Show your working out.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
File size: .......................................... kilobytes
[2]
(iii) State the minimum number of bits that will be needed to represent 240 different colours.
. ................................................................................................................................................. [1]
(c) The student wants to use a secondary storage device to move their files to their home computer.
Identify whether the student should use an optical or solid-state type of secondary storage
device. Justify your choice.
Optical or solid-state ...........................................................
Justification ......................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ................................................................................................................................................. [4]
© OCR 2025 Turn over
, 4
2 A computer has an operating system.
(a) Tick (✓) one box on each row to identify the operating system function that will manage each
task.
Operating system Memory Peripheral User File
function management management management management
Multitasking
Renaming a folder
Creation of user accounts
Installation of a printer
driver
Transfer of data to and
from RAM
[5]
(b) A computer also has utility software.
(i) State the purpose of utility software in a computer.
..........................................................................................................................................................
. ................................................................................................................................................. [1]
(ii) Explain the purpose and function of encryption software.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ................................................................................................................................................. [3]
© OCR 2025
All Assessment Questions & Mark Scheme [OCR J277/01]
Exam Resource Summary
The GCSE (9–1) Computer Science May 2025 Computer Systems Paper (OCR J277/01) merges the
full official examination paper with its detailed mark scheme to provide a clear and structured
revision resource. This paper assesses students’ understanding of key computer science concepts,
including hardware, software, networks, data representation, and system security. Candidates are
required to apply theoretical knowledge to problem-solving scenarios, interpret technical
information, and demonstrate logical reasoning and computational thinking. By presenting each
question alongside its marking criteria, the resource clarifies examiner expectations, highlights the
analytical and problem-solving skills required for high-band responses, and guides learners in
producing precise, well-structured answers. This integrated format supports focused revision,
reinforces core computer science principles, and prepares students thoroughly for the 2026 OCR
GCSE Computer Science Computer Systems examination.
OCR is an exempt Charity
Turn over
, 2
1 A student is creating a presentation containing images and sound.
(a) One of the files is an audio recording.
Complete the description of how a computer stores sound. Fill in the gaps using the given list of
terms. Not all terms will be used.
analogue colour depth higher repeated smaller
binary digital lower sample rate unique
bit depth height measuring sampling
byte hertz recording seconds
An .....................................................................sound wave needs to be converted into a digital
sound wave.
Sound .................................................................... is when the amplitude of the sound wave is
measured at set intervals.
The..................................................................... is the number of times a second the sound wave
is measured. This is given in Hertz.
Each amplitude is given a..................................................................... binary number. The
number of bits allocated to each sample is the ..................................................................... .
The..................................................................... the number of bits, the wider the number of
amplitudes can be measured.
[6]
© OCR 2025
, 3
(b) The student creates 10 bitmap images using a computer.
Each image has a colour depth of 8-bits and a resolution of 800 × 500 pixels.
(i) Define the term pixel.
..........................................................................................................................................................
. ................................................................................................................................................. [1]
(ii) Calculate the total file size of the 10 images in kilobytes.
Show your working out.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
File size: .......................................... kilobytes
[2]
(iii) State the minimum number of bits that will be needed to represent 240 different colours.
. ................................................................................................................................................. [1]
(c) The student wants to use a secondary storage device to move their files to their home computer.
Identify whether the student should use an optical or solid-state type of secondary storage
device. Justify your choice.
Optical or solid-state ...........................................................
Justification ......................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ................................................................................................................................................. [4]
© OCR 2025 Turn over
, 4
2 A computer has an operating system.
(a) Tick (✓) one box on each row to identify the operating system function that will manage each
task.
Operating system Memory Peripheral User File
function management management management management
Multitasking
Renaming a folder
Creation of user accounts
Installation of a printer
driver
Transfer of data to and
from RAM
[5]
(b) A computer also has utility software.
(i) State the purpose of utility software in a computer.
..........................................................................................................................................................
. ................................................................................................................................................. [1]
(ii) Explain the purpose and function of encryption software.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
. ................................................................................................................................................. [3]
© OCR 2025
