OCR GCSE Computer Science Sample Paper Walkthrough 🎓

Introduction

• Sample Paper: Created by OCR to give an idea of a real exam paper.
• Availability: Only paper available on OCR's website at time of recording.
• Recommendation: Try the paper on your own, in silence, for 1.5 hours.
• Marking Scheme: Available on OCR's website; essential for self-marking.
• Indicative Grade Boundaries: Suggested thresholds based on performance.
  • 90% = Grade 9
  • 80% = Grade 8

Exam Overview

• Paper Title: Computer Systems (Theoretical paper).
• Content Covered: Hardware, Software, Data Representation, Networking, Security, & Impacts.
• Total Marks: 80 marks, worth 50% of your grade.
• Duration: 90 minutes.
• Calculator: Not allowed.
• Answering Tips: Spend about a minute per mark, leaving 10 minutes for checking.
• Quality of Written Communication (QWC): Important for the long 8-mark question.

Sample Questions Breakdown

Question 1: CPU Comparison

Part A

• Question: Why is Computer 1 likely to run faster than Computer 2?
• Answer: Computer 1 has more cores, allowing for more parallel processing.

Part B

• Question: Identify two other parts of a computer that can improve performance.
• Answer:
  1. RAM (speed/size)
  2. Storage (SSD)

Part C

• Question: Why does cache size affect CPU performance?
• Answer: Bigger cache stores more instructions/data, which can be accessed faster.

Part D

• Question: Identify two events that take place during the fetch-execute cycle.
• Answer:
  1. Fetch: Instruction received from memory.
  2. Execute: Instruction carried out by the CPU.

Question 2: Secondary Storage

Part A

• Question: Define secondary storage.
• Answer: Long-term, non-volatile storage of data/files.

Part B

• Question: Identify three types of secondary storage.
• Answer:
  1. Magnetic
  2. Solid State
  3. Optical

Part C

• Question: Characteristics of secondary storage to consider.
• Answer:
  1. Speed
  2. Portability
  3. Reliability
  4. Durability

Question 3: RAM vs. ROM

Part A

• Question: Tick whether the statements are true for RAM or ROM.
• Answer:
  1. Stores boot-up sequence: ROM
  2. Contents lost when powered off: RAM
  3. Hosts open maps and routes: RAM

Part B

• Question: Define an embedded system.
• Answer: Special-purpose computer built into another device.

Part C

• Question: Identify three devices with embedded systems (other than satnav).
• Answer:
  1. Washing Machine
  2. Hot Tub
  3. Car

Question 4: Audio Recording

Part A

• Question: Describe the process of converting music to a file.
• Answer: Analog sound is sampled at regular intervals; samples are converted to binary.

Part B

• Question: Effects of increasing sample rate.
• Answer:
  1. Higher quality (closer to original).
  2. Larger file size.

Part C

• Question: Perform a 2-place shift right on a binary number.
• Answer: Lose two least significant bits, add two leading zeros.

Part D

• Question: Effect of performing a binary right shift.
• Answer: Dividing by 4 (for two shifts); leads to rounding down (losing fraction).

Question 5: ASCII Representation

• Describe the process for representing a word in ASCII.
• Answer: Each character is converted to an ASCII code and stored in binary (8 bits per code).

Question 6: Networking

Part A

• Question: Define a network protocol.
• Answer: Set of agreed rules for communication between devices.

Part B

• Question: Define a layer in network protocols.
• Answer: Aspect of communication functionality; self-contained job in the process.

Part C

• Question: Advantages of using layers.
• Answer:
  1. Changes can be made to one layer without affecting others.
  2. Better compatibility between different protocols.

Question 7: Star Topology

Part A

• Question: Benefits of using a star topology.
• Answer:
  1. Easy to add new devices.
  2. Failure of one device doesn't affect the network.

Question 8: Security Measures

Part A

• Question: Explain three ways a hospital could protect its network.
• Answer:
  1. Encryption: Makes data unreadable without decryption key.
  2. Firewalls: Block suspicious traffic.
  3. Anti-malware software: Detect and remove malware.

Part B

• Question: Identify three errors staff could make that endanger security and a procedure to prevent each.
• Answer:
  1. Leaving server rooms unlocked; Procedure: Use swipe cards.
  2. Downloading from suspicious websites; Procedure: Ban certain websites.
  3. Connecting infected personal devices; Procedure: Ban personal devices.

Question 9: Disk Fragmentation

Part A

• Question: Explain how a hard disk becomes fragmented.
• Answer: Files are split and stored in multiple locations due to gaps left by deleted files.

Part B

• Question: How does defragmentation software solve fragmentation?
• Answer: Moves split files to be stored together, reducing time to read files.

Question 10: Cloud Storage

Part A

• Question: Define a wide area network (WAN).
• Answer: Network over a large geographical area with shared infrastructure.

Part B

• Question: Advantages of cloud storage for a law company.
• Answer:
  1. Easily scalable; can pay for more storage as needed.
  2. Access data from anywhere; useful for remote work.

Part C

• Question: Disadvantages of cloud storage for a law company.
• Answer:
  1. Needs internet connection; problematic in remote locations.
  2. Reliant on cloud provider for security; potential risk to reputation.

Part D

• Question: Match legislation to actions.
• Answer:
  1. Copyright Designs and Patents Act: Using a picture without permission.
  2. Computer Misuse Act: Accessing personal email without permission.
  3. Data Protection Act: Storing customer data insecurely.

Question 11: Impacts of Upgrading Smartphones

Part A

• Question: Discuss the impact of upgrading smartphones.
• Considerations: Impact on users, cultural issues, ethical issues, environmental issues.
• Answer:
  1. Performance Improvement: Latest phones offer better performance.
  2. Unethical Slowdown: Manufacturers may slow down older phones intentionally.
  3. Cultural Peer Pressure: Pressure to upgrade due to trends and advertising.
  4. Environmental Impact: Phones may end up in landfill but could be recycled.

Final Tips

• Check Your Answers: Use leftover time to review for mistakes.
• Time Management: Aim to complete with 10 minutes to spare for checking.
• Answer All Questions: Attempt every question, even if unsure.
• Stay Calm: Confidence can improve your performance.