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Daily Practice · GCSE Computer Science

July 2017 - GCSE Computer Science 5-a-day

Every GCSE Computer Science sheet published in July 2017, with answers. Systems, data representation, networks, algorithms and programming.

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July 2017

31 sheets · 155 questions · GCSE

July 2017 compilationAll answers

Every sheet in July 2017

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

  1. 1st July 2017A simple cipher shifts every letter 2 places forward in the alphabet, wrapping around so Y becomes A and Z becomes B. Encrypt the plaintext CAT using this cipher.
  2. 2nd July 2017Describe what a nested loop does when it processes a 2D array.
  3. 3rd July 2017A mono sound clip has a sample rate of 4000 Hz and lasts 2 seconds. Calculate the total number of samples taken.
  4. 4th July 2017State the type of program that is typically stored in ROM.
  5. 5th July 2017State one reason a small business might choose to use open source software instead of proprietary (closed source) software.
  6. 6th July 2017A FOR loop runs: total = 0, FOR i = 1 TO 4, total = total + i, NEXT i. State the value of total after the loop finishes.
  7. 7th July 2017State the pseudocode operator commonly used to join (concatenate) two strings, then show how it joins 'Rev' and 'ision' to produce 'Revision'.
  8. 8th July 2017State the typical maximum capacity of a single-layer DVD.
  9. 9th July 2017Give two reasons why network communication is divided into layers.
  10. 10th July 2017State what is meant by a syntax error.
  11. 11th July 2017Define the term 'primary key' as used in a database table.
  12. 12th July 2017What type of utility software reorganises files on a hard disk so fragmented parts are stored closer together?
  13. 13th July 2017Calculate the maximum number of comparisons required by a binary search on a sorted list of 512 items.
  14. 14th July 2017Given P = 0 and Q = 1, state the value of P OR Q.
  15. 15th July 2017Convert the 8-bit binary number 10110100 directly to hexadecimal by splitting it into nibbles.
  16. 16th July 2017A network administrator is connecting 10 computers in a server room. Calculate the number of cables needed for a full mesh topology, and state the number needed for a star topology with one central switch.
  17. 17th July 2017Explain why an interpreter is often preferred while a program is being written.
  18. 18th July 2017Convert the 4-bit binary number 1101 to denary.
  19. 19th July 2017Two 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.
  20. 20th July 2017State why an organisation might employ penetration testers to test its network.
  21. 21st July 2017A 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.
  22. 22nd July 2017State one example of a file format that commonly uses lossy compression.
  23. 23rd July 2017State how many bits are in one byte, and how many bytes are in one kibibyte (KiB).
  24. 24th July 2017State whether the source code of proprietary (closed source) software is normally available for the public to view.
  25. 25th July 2017Write one line of pseudocode that converts the string stored in heightInput into a real number and stores it in a variable called height.
  26. 26th July 2017A function is defined as: FUNCTION addTax(price) RETURN price x 1.2 ENDFUNCTION. Another line of code runs: total <- addTax(20) + addTax(30). Trace both function calls and state the final value of total.
  27. 27th July 2017Order these units of data from smallest to largest: megabyte, byte, gigabyte, kilobyte.
  28. 28th July 2017State the layer that IP operates in, and describe its job.
  29. 29th July 2017Give one example of erroneous test data for a field that only accepts whole numbers from 1 to 10.
  30. 30th July 2017A table called staff has fields staffId, name, department and salary, storing these records: staffId | name | department | salary, 1 | Ben | Sales | 24000, 2 | Chloe | IT | 31000, 3 | Dan | Sales | 27000. State which staffId(s) would be returned by: SELECT staffId FROM staff WHERE department = 'Sales' AND salary > 25000;
  31. 31st July 2017Each 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.