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Electronics Worksheet: Loops and Variables

Electronics lesson 25: Loops and variables · Set 498 · 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.🔁 What does “count = count + 1” do? (a) takes 1 away (b) prints 1 (c) adds 1 to count (d) sets count to 1
  2. 2.🔁 count = 4
    repeat 3 times { count = count + 4 }
    What is count at the end?
  3. 3.🔁 count = 1
    while (count < 21) { count = count + 4 }
    How many times does the loop run?
  4. 4.🔁 repeat 5 times { repeat 3 times { beep } }
    How many beeps are there?
  5. 5.🔁 count = 4
    while (count < 25) { count = count + 3 }
    How many times does the loop run?
  6. 6.🔁 repeat 4 times { repeat 2 times { beep } }
    How many beeps are there?
  7. 7.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
  8. 8.🔁 x = 4
    repeat 3 times { x = x × 2 }
    What is x at the end?
  9. 9.🔁 total = 0
    for i = 1 to 3 { total = total + i }
    What is total at the end?
  10. 10.🔁 What does a variable do in a program? (a) measures light (b) stores a value (c) blinks an LED (d) joins two wires
  11. 11.🔁 x = 1
    repeat 5 times { x = x × 2 }
    What is x at the end?
  12. 12.🔁 count = 0
    repeat 6 times { count = count + 7 }
    What is count at the end?
  13. 13.🔁 repeat 5 times { repeat 6 times { beep } }
    How many beeps are there?
  14. 14.🔁 x = 2
    repeat 3 times { x = x × 2 }
    What is x at the end?
  15. 15.🔁 repeat 4 times { repeat 6 times { beep } }
    How many beeps are there?
  16. 16.🔁 repeat 6 times { repeat 3 times { beep } }
    How many beeps are there?
  17. 17.🔁 count = 5
    while (count < 20) { count = count + 3 }
    How many times does the loop run?
  18. 18.🔁 total = 0
    for i = 1 to 10 { total = total + i }
    What is total at the end?
  19. 19.🔁 count = 0
    while (count < 15) { count = count + 3 }
    How many times does the loop run?
  20. 20.🔁 count = 0
    while (count < 15) { count = count + 5 }
    How many times does the loop run?
  21. 21.🔁 count = 5
    while (count < 17) { count = count + 4 }
    How many times does the loop run?
  22. 22.🔁 count = 4
    repeat 8 times { count = count + 2 }
    What is count at the end?
  23. 23.🔁 total = 0
    for i = 1 to 8 { total = total + i }
    What is total at the end?
  24. 24.🔁 count = 1
    repeat 8 times { count = count + 6 }
    What is count at the end?
  25. 25.🔁 x = 5
    repeat 5 times { x = x × 2 }
    What is x at the end?
  26. 26.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
  27. 27.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
  28. 28.🔁 count = 1
    while (count < 11) { count = count + 5 }
    How many times does the loop run?
  29. 29.🔁 count = 2
    while (count < 10) { count = count + 4 }
    How many times does the loop run?
  30. 30.🔁 count = 10
    repeat 3 times { count = count + 3 }
    What is count at the end?
  31. 31.🔁 total = 0
    for i = 1 to 12 { total = total + i }
    What is total at the end?
  32. 32.🔁 x = 1
    repeat 1 time { x = x × 2 }
    What is x at the end?
  33. 33.🔁 repeat 2 times { repeat 3 times { beep } }
    How many beeps are there?
  34. 34.🔁 x = 2
    repeat 4 times { x = x × 2 }
    What is x at the end?
  35. 35.🔁 count = 5
    while (count < 30) { count = count + 5 }
    How many times does the loop run?
  36. 36.🔁 count = 9
    repeat 6 times { count = count + 3 }
    What is count at the end?
  37. 37.🔁 count = 6
    repeat 7 times { count = count + 5 }
    What is count at the end?
  38. 38.🔁 x = 3
    repeat 1 time { x = x × 2 }
    What is x at the end?
  39. 39.🔁 count = 0
    while (count < 28) { count = count + 4 }
    How many times does the loop run?
  40. 40.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?

Answer key

  1. adds 1 to count
  2. 16
  3. 5
  4. 15
  5. 7
  6. 8
  7. 28
  8. 32
  9. 6
  10. stores a value
  11. 32
  12. 42
  13. 30
  14. 16
  15. 24
  16. 18
  17. 5
  18. 55
  19. 5
  20. 3
  21. 3
  22. 20
  23. 36
  24. 49
  25. 160
  26. 4
  27. 21
  28. 2
  29. 2
  30. 19
  31. 78
  32. 2
  33. 6
  34. 32
  35. 5
  36. 27
  37. 41
  38. 6
  39. 7
  40. 18

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