← Loops and variables lesson New set →

Electronics Worksheet: Loops and Variables

Electronics lesson 25: Loops and variables · Set 235 · 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 6 { total = total + i }
    What is total at the end?
  2. 2.🔁 What does a variable do in a program? (a) measures light (b) joins two wires (c) blinks an LED (d) stores a value
  3. 3.🔁 x = 3
    repeat 1 time { x = x × 2 }
    What is x at the end?
  4. 4.🔁 count = 7
    repeat 2 times { count = count + 7 }
    What is count at the end?
  5. 5.🔁 total = 0
    for i = 1 to 12 { total = total + i }
    What is total at the end?
  6. 6.🔁 count = 8
    repeat 2 times { count = count + 9 }
    What is count at the end?
  7. 7.🔁 x = 4
    repeat 3 times { x = x × 2 }
    What is x at the end?
  8. 8.🔁 total = 0
    for i = 1 to 10 { total = total + i }
    What is total at the end?
  9. 9.🔁 count = 1
    repeat 9 times { count = count + 4 }
    What is count at the end?
  10. 10.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
  11. 11.🔁 repeat 2 times { repeat 4 times { beep } }
    How many beeps are there?
  12. 12.🔁 x = 2
    repeat 4 times { x = x × 2 }
    What is x at the end?
  13. 13.🔁 x = 3
    repeat 2 times { x = x × 2 }
    What is x at the end?
  14. 14.🔁 repeat 5 times { repeat 4 times { beep } }
    How many beeps are there?
  15. 15.🔁 x = 2
    repeat 5 times { x = x × 2 }
    What is x at the end?
  16. 16.🔁 x = 1
    repeat 2 times { x = x × 2 }
    What is x at the end?
  17. 17.🔁 count = 4
    while (count < 8) { count = count + 2 }
    How many times does the loop run?
  18. 18.🔁 count = 2
    while (count < 11) { count = count + 3 }
    How many times does the loop run?
  19. 19.🔁 count = 5
    while (count < 13) { count = count + 2 }
    How many times does the loop run?
  20. 20.🔁 repeat 4 times { repeat 2 times { beep } }
    How many beeps are there?
  21. 21.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
  22. 22.🔁 x = 1
    repeat 1 time { x = x × 2 }
    What is x at the end?
  23. 23.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) prints 1 (c) sets count to 1 (d) takes 1 away
  24. 24.🔁 count = 1
    while (count < 36) { count = count + 5 }
    How many times does the loop run?
  25. 25.🔁 x = 5
    repeat 3 times { x = x × 2 }
    What is x at the end?
  26. 26.🔁 repeat 2 times { repeat 5 times { beep } }
    How many beeps are there?
  27. 27.🔁 count = 0
    while (count < 12) { count = count + 2 }
    How many times does the loop run?
  28. 28.🔁 x = 4
    repeat 4 times { x = x × 2 }
    What is x at the end?
  29. 29.🔁 total = 0
    for i = 1 to 11 { total = total + i }
    What is total at the end?
  30. 30.🔁 repeat 4 times { repeat 5 times { beep } }
    How many beeps are there?
  31. 31.🔁 count = 1
    repeat 7 times { count = count + 10 }
    What is count at the end?
  32. 32.🔁 repeat 6 times { repeat 5 times { beep } }
    How many beeps are there?
  33. 33.🔁 repeat 5 times { repeat 6 times { beep } }
    How many beeps are there?
  34. 34.🔁 x = 3
    repeat 5 times { x = x × 2 }
    What is x at the end?
  35. 35.🔁 count = 4
    while (count < 29) { count = count + 5 }
    How many times does the loop run?
  36. 36.🔁 x = 1
    repeat 5 times { x = x × 2 }
    What is x at the end?
  37. 37.🔁 count = 4
    repeat 5 times { count = count + 8 }
    What is count at the end?
  38. 38.🔁 count = 0
    while (count < 10) { count = count + 2 }
    How many times does the loop run?
  39. 39.🔁 count = 1
    repeat 5 times { count = count + 2 }
    What is count at the end?
  40. 40.🔁 count = 6
    repeat 4 times { count = count + 2 }
    What is count at the end?

Answer key

  1. 21
  2. stores a value
  3. 6
  4. 21
  5. 78
  6. 26
  7. 32
  8. 55
  9. 37
  10. 10
  11. 8
  12. 32
  13. 12
  14. 20
  15. 64
  16. 4
  17. 2
  18. 3
  19. 4
  20. 8
  21. 28
  22. 2
  23. adds 1 to count
  24. 7
  25. 40
  26. 10
  27. 6
  28. 64
  29. 66
  30. 20
  31. 71
  32. 30
  33. 30
  34. 96
  35. 5
  36. 32
  37. 44
  38. 5
  39. 11
  40. 14

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids