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Daily Practice · GCSE Computer Science

October 1991 5-a-day

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October 1991

31 sheets · 155 questions · GCSE

October 1991 compilationAll answers

Every sheet in October 1991

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

  1. 1st October 1991State one weakness of a simple shift cipher compared to modern encryption methods used on networks.
  2. 2nd October 1991Trace 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).
  3. 3rd October 1991Define the term 'pixel'.
  4. 4th October 1991Order these from fastest access speed to slowest: RAM, cache, registers, secondary storage.
  5. 5th October 1991Which piece of UK legislation makes it a criminal offence to gain unauthorised access to a computer system?
  6. 6th October 1991Evaluate the expression 23 DIV 4.
  7. 7th October 1991A 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.
  8. 8th October 1991A 1 TB hard disk drive costs 40 pounds. A 500 GB solid-state drive costs 60 pounds. Calculate the cost per gigabyte of each device, and state which is cheaper per GB. Use 1 TB = 1000 GB.
  9. 9th October 1991Explain the role of TCP when a large file is downloaded.
  10. 10th October 1991A 'quantity' field on a website must only accept whole numbers from 1 to 10. Which validation check identifies that 15 has been entered?
  11. 11th October 1991A 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;
  12. 12th October 1991A row of 8 pixels is WWWBBBWW. Use run-length encoding to encode this row as pairs of (colour, run length).
  13. 13th October 1991An 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.
  14. 14th October 1991Complete: NOT 0 = ?
  15. 15th October 1991Convert the 8-bit binary number 01011010 to denary.
  16. 16th October 1991State what LAN stands for.
  17. 17th October 1991Give one advantage and one disadvantage of using a compiler.
  18. 18th October 1991An 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.
  19. 19th October 1991Which CPU register holds the address of the next instruction to be fetched?
  20. 20th October 1991Distinguish between the network security threats known as phishing and pharming.
  21. 21st October 1991Write a loop in pseudocode that outputs every element of a 1D array named names of length 6.
  22. 22nd October 1991A row of pixels is encoded using run-length encoding as: 3W 4B 3W. State the original row of pixels it represents.
  23. 23rd October 1991A photo file is 3.5 MB in size. Calculate its size in kilobytes (KB). Use 1 MB = 1000 KB.
  24. 24th October 1991A 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.
  25. 25th October 1991State the most appropriate data type for storing a person's shoe size if only whole sizes (e.g. 7, 8, 9) are allowed.
  26. 26th October 1991Write 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.
  27. 27th October 1991Give one example of an optical secondary storage device.
  28. 28th October 1991A user reads the same email on a phone and a tablet, and deleting it on one deletes it on the other. Which protocol is in use and why?
  29. 29th October 1991State the term used for realistic data that a program would be expected to handle during normal use.
  30. 30th October 1991State what a foreign key is used for.
  31. 31st October 1991State the difference between lossy and lossless compression.