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Daily Practice · GCSE Computer Science

July 2015 - GCSE Computer Science 5-a-day

Every GCSE Computer Science sheet published in July 2015, with answers. Systems, data representation, networks, algorithms and programming.

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July 2015

31 sheets · 155 questions · GCSE

July 2015 compilationAll answers

Every sheet in July 2015

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 2015A 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;
  2. 2nd July 2015A row of 8 pixels is WWWBBBWW. Use run-length encoding to encode this row as pairs of (colour, run length).
  3. 3rd July 2015An array contains [9, 2, 6], to be sorted using insertion sort. Show the state of the array after each new element has been inserted into its correct position.
  4. 4th July 2015Complete: NOT 0 = ?
  5. 5th July 2015Convert the 8-bit binary number 01011010 to denary.
  6. 6th July 2015State what LAN stands for.
  7. 7th July 2015Name the translator used for assembly language and describe how it differs from a compiler.
  8. 8th July 2015An 8-bit register stores the value 01100000 (denary 96). State the resulting 8-bit binary value after a left shift by 1 place, and state whether an overflow occurs.
  9. 9th July 2015Which CPU register holds the address of the next instruction to be fetched?
  10. 10th July 2015Distinguish between the network security threats known as phishing and pharming.
  11. 11th July 2015Explain what happens if a program tries to read index 5 of an array declared with 5 elements.
  12. 12th July 2015A row of pixels is encoded using run-length encoding as: 3W 4B 3W. State the original row of pixels it represents.
  13. 13th July 2015A photo file is 3.5 MB in size. Calculate its size in kilobytes (KB). Use 1 MB = 1000 KB.
  14. 14th July 2015A streaming company records which shows each user watches and uses this to recommend similar shows. Explain one ethical concern this could raise, even if the company only uses the data to improve recommendations.
  15. 15th July 2015State the most appropriate data type for storing a person's shoe size if only whole sizes (e.g. 7, 8, 9) are allowed.
  16. 16th July 2015Write the pseudocode header and body for a function called isAdult that takes one integer parameter called age and returns True if age is 18 or over.
  17. 17th July 2015Give one example of an optical secondary storage device.
  18. 18th July 2015Define the term protocol.
  19. 19th July 2015State the term used for realistic data that a program would be expected to handle during normal use.
  20. 20th July 2015State what a foreign key is used for.
  21. 21st July 2015State the difference between lossy and lossless compression.
  22. 22nd July 2015State the condition that must be met before a binary search can be used on an array.
  23. 23rd July 2015A logic circuit has inputs C and D. C feeds into a NOT gate; the output of the NOT gate and D feed into an OR gate, giving output Y. Write the Boolean expression for Y and state its value when C = 1 and D = 0.
  24. 24th July 2015A pseudocode algorithm is: count <- 0, x <- 10, WHILE x > 0, count <- count + 1, x <- x - 3, ENDWHILE, OUTPUT count. Complete a trace table for x and count, laid out as x | count, then state the value output.
  25. 25th July 2015Which piece of network hardware connects a LAN to another network such as the internet, directing data packets based on IP address?
  26. 26th July 2015Explain the purpose of a breakpoint.
  27. 27th July 2015Convert the denary number 45 to hexadecimal.
  28. 28th July 2015What does the acronym CPU stand for?
  29. 29th July 2015State what the term malware means.
  30. 30th July 2015Explain why a running maximum should be initialised to the first element of the array rather than to 0.
  31. 31st July 2015An uncompressed file is 6000 KB. After lossless compression it is 1500 KB. Calculate the compression ratio in the form n:1 (original size : compressed size).