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Daily Practice · GCSE Computer Science

December 2021 - GCSE Computer Science 5-a-day

Every GCSE Computer Science sheet published in December 2021, with answers. Systems, data representation, networks, algorithms and programming.

← Today's GCSE Computer Science sheet

December 2021

31 sheets · 155 questions · GCSE

December 2021 compilationAll answers

Every sheet in December 2021

The same date always regenerates the same five questions, so a sheet you print today is the sheet a classmate prints tomorrow.

  1. 1st December 2021Two CPUs are compared for a task optimised for multiple cores: CPU A has 2 cores at 4.2 GHz; CPU B has 6 cores at 3.0 GHz. Explain which CPU is likely to perform better for this task.
  2. 2nd December 2021State why an organisation might employ penetration testers to test its network.
  3. 3rd December 2021A 2D array grid is declared as grid[4][6]. State how many rows and columns it has and how many elements it holds in total.
  4. 4th December 2021State one example of a file format that commonly uses lossy compression.
  5. 5th December 2021State how many bits are in one byte, and how many bytes are in one kibibyte (KiB).
  6. 6th December 2021State whether the source code of proprietary (closed source) software is normally available for the public to view.
  7. 7th December 2021Write one line of pseudocode that converts the string stored in heightInput into a real number and stores it in a variable called height.
  8. 8th December 2021A programmer wants any syntax error in their program to be reported before the program starts running at all. State whether a compiler or an interpreter behaves this way, and explain why.
  9. 9th December 2021Order these units of data from smallest to largest: megabyte, byte, gigabyte, kilobyte.
  10. 10th December 2021State the layer that IP operates in, and describe its job.
  11. 11th December 2021Give one example of erroneous test data for a field that only accepts whole numbers from 1 to 10.
  12. 12th December 2021A table called bookings has fields bookingId, customerName and eventDate. Write an SQL statement that deletes the booking with bookingId 45.
  13. 13th December 2021Each pair from the previous question is stored using 2 bytes. Calculate the compression ratio achieved, given the uncompressed row (1 byte per pixel) uses 8 bytes.
  14. 14th December 2021Which flowchart symbol shape is used to represent a decision point (e.g. a yes/no branch)?
  15. 15th December 2021State the two values a Boolean data type can hold.
  16. 16th December 2021Convert the denary number 39 to an 8-bit binary number, showing your working.
  17. 17th December 2021Calculate the number of cables needed to connect 8 computers in a full mesh topology, where every computer connects directly to every other computer.
  18. 18th December 2021Describe what syntax highlighting is and how it helps a programmer.
  19. 19th December 2021Convert the hexadecimal number 1A to denary.
  20. 20th December 2021Convert the denary number 156 to an 8 bit binary number.
  21. 21st December 2021Which type of malware can replicate itself and spread across a network without attaching to another program or needing a user to run it?
  22. 22nd December 2021Trace this algorithm with data = [4, 9, 2, 9, 7] and state the final output. total = 0; count = 0; for i = 0 to 4: if data[i] > 5 then total = total + data[i] and count = count + 1; next i; print(total, count).
  23. 23rd December 2021An image uses a colour depth of 2 bits per pixel. Calculate the maximum number of different colours it can represent.
  24. 24th December 2021A CPU's cache has a hit rate of 80%. During a task the CPU makes 4000 requests for data. Calculate the number of cache hits and cache misses.
  25. 25th December 2021Describe two negative consequences of throwing away old computer hardware instead of recycling it.
  26. 26th December 2021Write a function called isEven that takes one integer parameter, num, and returns True if num is even and False otherwise.
  27. 27th December 2021Give one specific way this code could be refined without changing what it does: a = 5, b = 3, c = a + b, PRINT c
  28. 28th December 2021A company backs up its files onto magnetic tape cartridges, each with a capacity of 3 TB. The company needs to back up 20 TB of data. Calculate the minimum number of cartridges needed.
  29. 29th December 2021Explain the role of TCP when a large file is downloaded.
  30. 30th December 2021Explain why iterative testing, carried out throughout development, tends to make errors cheaper to fix than relying only on final testing.
  31. 31st December 2021A table called members has fields memberId, firstName, lastName and joinYear. Write an SQL statement that adds a new record with memberId 12, firstName 'Priya', lastName 'Shah' and joinYear 2026.