About this practice. Revision Robin is built and maintained by Bloor Engineering Ltd, a UK-registered company. Our GCSE Computer Science (OCR) questions are written and reviewed in-house to match the current syllabus, each with a plain-English worked explanation. They are original practice material, not the official exam questions and not affiliated with or endorsed by OCR. Always confirm current test rules, fees and content with the official provider. See our Terms and Privacy.
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Free practice questions
Try 3 real GCSE Computer Science (OCR) questions
Have a go, then reveal the worked explanation. A taster from a bank of 212 original questions. Unlock for unlimited drills and full timed mocks.
Q1. Which term describes breaking a large problem down into a series of smaller, more manageable sub-problems?
A. Abstraction
B. Decomposition
C. Pattern recognition
D. Backtracking
Show answer & explanation
✓ Answer: B. Decomposition
Decomposition is the process of splitting a complex problem into smaller sub-problems that are easier to solve individually. Abstraction is a different technique that involves removing unnecessary detail, not splitting the problem up.
Q2. A programmer declares an array: scores = [45, 67, 23, 89, 12]. What is the value of scores[2] if the array is zero-indexed, as in OCR's pseudocode?
A. 45
B. 67
C. 23
D. 89
Show answer & explanation
✓ Answer: C. 23
With zero-indexing the first element is scores[0], so scores[0]=45, scores[1]=67 and scores[2]=23. Students who mistakenly count from 1 often pick 67, which would only be correct under one-based indexing.
Q3. Why might an image using a higher colour depth still appear identical on screen to one using a lower colour depth, despite having a larger file size?
A. Colour depth has no effect on file size at all
B. If the original image only used a small range of colours to begin with, the extra colour depth adds no visible difference but still reserves more bits per pixel
C. Higher colour depth always reduces file size
D. Screens cannot display more than 16 colours regardless of colour depth
Show answer & explanation
✓ Answer: B. If the original image only used a small range of colours to begin with, the extra colour depth adds no visible difference but still reserves more bits per pixel
Colour depth sets the maximum number of colours that could be used per pixel, but if an image such as a simple black-and-white logo doesn't actually use that full range, increasing the colour depth still reserves more bits per pixel in storage without adding any visible detail. This illustrates why choosing an appropriate colour depth for the content matters for efficient storage.
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The first 8 of 40 questions are free, with your score on them. Finishing the paper, your result against the pass mark and every answer explained come with the paid version.
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Who has to sit the GCSE Computer Science (OCR)
Who needs a GCSE Computer Science (OCR)?
No one; it is not a compulsory GCSE to pass. Students choose it as an option, often for further education or careers in tech.
The real GCSE Computer Science (OCR): format
How long is the GCSE Computer Science (OCR)?
The real GCSE Computer Science (OCR) lasts 180 minutes. Our mock uses 40 questions in 60 minutes.
What is the GCSE Computer Science (OCR) pass mark?
Real exam pass mark: Grade 4 (approx. 77 marks out of 160 total for June 2026). Our mock marks you at 24 out of 40, the threshold we mark against.
What it costs, and what a resit costs
How much does the GCSE Computer Science (OCR) cost?
Real exam fee: £150-£230+ (private candidate). Resit fee: £150-£230+ (private candidate). Rebooking after a fail: Resits typically available in May/June only, with registration deadline in mid-February.
How hard is it
What is the GCSE Computer Science (OCR) pass rate?
Real exam first-time pass rate: 70.8% achieved Grade 4 or above in 2026 (across all boards). Difficulty: Challenging; involves abstract concepts, problem-solving, and programming logic. Examiner reports show struggles with application and multi-step questions.
Why people fail it
Why do people fail the GCSE Computer Science (OCR)?
Lack of precision, vague answers, not showing working, or misunderstanding command words.
Figures for the real exam from vertexaisearch.cloud.google.com, checked October 2026. Fees and rules change, so confirm with the test provider before you book.
GCSE Computer Science (OCR): common questions
Frequently asked
How many questions are in the GCSE Computer Science (OCR)?
The exam has 40 questions. Every Revision Robin mock uses the same 40-question format so your practice matches the real thing.
Are these the real exam questions?
No. Our questions are original and written to match the current syllabus, so they give realistic practice without copying the official paper. Every answer comes with a plain-English explanation. Always confirm current rules and content with OCR.