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Electronics Worksheet: Loops and Variables

Electronics lesson 25: Loops and variables · Set 274 · 40 questions
TalentJR

Remember (Trace every pass): count = count + k adds k each time round; after n rounds: start + n × k. A loop inside a loop runs outer × inner times. while (condition) repeats until the condition is false — count the rounds as you trace.

NameDateTime takenScore ___ / 40
  1. 1.🔁 total = 0
    for i = 1 to 3 { total = total + i }
    What is total at the end?
  2. 2.🔁 count = 3
    while (count < 15) { count = count + 2 }
    How many times does the loop run?
  3. 3.🔁 x = 3
    repeat 3 times { x = x × 2 }
    What is x at the end?
  4. 4.🔁 repeat 2 times { repeat 6 times { beep } }
    How many beeps are there?
  5. 5.🔁 count = 3
    while (count < 18) { count = count + 3 }
    How many times does the loop run?
  6. 6.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) takes 1 away (c) prints 1 (d) sets count to 1
  7. 7.🔁 What does a variable do in a program? (a) joins two wires (b) blinks an LED (c) measures light (d) stores a value
  8. 8.🔁 count = 3
    while (count < 18) { count = count + 5 }
    How many times does the loop run?
  9. 9.🔁 count = 4
    while (count < 19) { count = count + 3 }
    How many times does the loop run?
  10. 10.🔁 total = 0
    for i = 1 to 8 { total = total + i }
    What is total at the end?
  11. 11.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?
  12. 12.🔁 repeat 6 times { repeat 2 times { beep } }
    How many beeps are there?
  13. 13.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
  14. 14.🔁 count = 6
    repeat 3 times { count = count + 2 }
    What is count at the end?
  15. 15.🔁 repeat 5 times { repeat 2 times { beep } }
    How many beeps are there?
  16. 16.🔁 repeat 4 times { repeat 3 times { beep } }
    How many beeps are there?
  17. 17.🔁 total = 0
    for i = 1 to 12 { total = total + i }
    What is total at the end?
  18. 18.🔁 count = 6
    repeat 6 times { count = count + 4 }
    What is count at the end?
  19. 19.🔁 repeat 5 times { repeat 3 times { beep } }
    How many beeps are there?
  20. 20.🔁 count = 2
    repeat 10 times { count = count + 8 }
    What is count at the end?
  21. 21.🔁 x = 3
    repeat 5 times { x = x × 2 }
    What is x at the end?
  22. 22.🔁 repeat 6 times { repeat 5 times { beep } }
    How many beeps are there?
  23. 23.🔁 x = 2
    repeat 1 time { x = x × 2 }
    What is x at the end?
  24. 24.🔁 x = 2
    repeat 3 times { x = x × 2 }
    What is x at the end?
  25. 25.🔁 x = 1
    repeat 1 time { x = x × 2 }
    What is x at the end?
  26. 26.🔁 repeat 6 times { repeat 3 times { beep } }
    How many beeps are there?
  27. 27.🔁 x = 5
    repeat 1 time { x = x × 2 }
    What is x at the end?
  28. 28.🔁 repeat 4 times { repeat 6 times { beep } }
    How many beeps are there?
  29. 29.🔁 count = 3
    repeat 10 times { count = count + 7 }
    What is count at the end?
  30. 30.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
  31. 31.🔁 count = 4
    while (count < 28) { count = count + 3 }
    How many times does the loop run?
  32. 32.🔁 count = 3
    while (count < 31) { count = count + 4 }
    How many times does the loop run?
  33. 33.🔁 total = 0
    for i = 1 to 11 { total = total + i }
    What is total at the end?
  34. 34.🔁 count = 4
    while (count < 32) { count = count + 4 }
    How many times does the loop run?
  35. 35.🔁 count = 3
    repeat 10 times { count = count + 8 }
    What is count at the end?
  36. 36.🔁 x = 4
    repeat 1 time { x = x × 2 }
    What is x at the end?
  37. 37.🔁 repeat 5 times { repeat 6 times { beep } }
    How many beeps are there?
  38. 38.🔁 x = 4
    repeat 3 times { x = x × 2 }
    What is x at the end?
  39. 39.🔁 count = 3
    repeat 3 times { count = count + 4 }
    What is count at the end?
  40. 40.🔁 repeat 3 times { repeat 4 times { beep } }
    How many beeps are there?

Answer key

  1. 6
  2. 6
  3. 24
  4. 12
  5. 5
  6. adds 1 to count
  7. stores a value
  8. 3
  9. 5
  10. 36
  11. 18
  12. 12
  13. 10
  14. 12
  15. 10
  16. 12
  17. 78
  18. 30
  19. 15
  20. 82
  21. 96
  22. 30
  23. 4
  24. 16
  25. 2
  26. 18
  27. 10
  28. 24
  29. 73
  30. 4
  31. 8
  32. 7
  33. 66
  34. 7
  35. 83
  36. 8
  37. 30
  38. 32
  39. 15
  40. 12

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