← Loops and variables lesson New set →

Electronics Worksheet: Loops and Variables

Electronics lesson 25: Loops and variables · Set 54 · 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.🔁 count = 3
    while (count < 9) { count = count + 2 }
    How many times does the loop run?
  2. 2.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) joins two wires (d) measures light
  3. 3.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
  4. 4.🔁 count = 10
    repeat 8 times { count = count + 2 }
    What is count at the end?
  5. 5.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
  6. 6.🔁 repeat 3 times { repeat 2 times { beep } }
    How many beeps are there?
  7. 7.🔁 total = 0
    for i = 1 to 11 { total = total + i }
    What is total at the end?
  8. 8.🔁 count = 3
    while (count < 43) { count = count + 5 }
    How many times does the loop run?
  9. 9.🔁 count = 5
    repeat 4 times { count = count + 2 }
    What is count at the end?
  10. 10.🔁 count = 8
    repeat 8 times { count = count + 3 }
    What is count at the end?
  11. 11.🔁 x = 5
    repeat 4 times { x = x × 2 }
    What is x at the end?
  12. 12.🔁 repeat 6 times { repeat 4 times { beep } }
    How many beeps are there?
  13. 13.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
  14. 14.🔁 count = 0
    while (count < 32) { count = count + 4 }
    How many times does the loop run?
  15. 15.🔁 count = 0
    repeat 6 times { count = count + 9 }
    What is count at the end?
  16. 16.🔁 count = 8
    repeat 7 times { count = count + 8 }
    What is count at the end?
  17. 17.🔁 x = 3
    repeat 2 times { x = x × 2 }
    What is x at the end?
  18. 18.🔁 x = 2
    repeat 3 times { x = x × 2 }
    What is x at the end?
  19. 19.🔁 repeat 3 times { repeat 3 times { beep } }
    How many beeps are there?
  20. 20.🔁 total = 0
    for i = 1 to 8 { total = total + i }
    What is total at the end?
  21. 21.🔁 What does “count = count + 1” do? (a) prints 1 (b) takes 1 away (c) adds 1 to count (d) sets count to 1
  22. 22.🔁 count = 7
    repeat 2 times { count = count + 10 }
    What is count at the end?
  23. 23.🔁 count = 0
    while (count < 30) { count = count + 5 }
    How many times does the loop run?
  24. 24.🔁 count = 1
    while (count < 9) { count = count + 4 }
    How many times does the loop run?
  25. 25.🔁 x = 5
    repeat 5 times { x = x × 2 }
    What is x at the end?
  26. 26.🔁 count = 1
    repeat 2 times { count = count + 3 }
    What is count at the end?
  27. 27.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
  28. 28.🔁 count = 1
    while (count < 16) { count = count + 3 }
    How many times does the loop run?
  29. 29.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
  30. 30.🔁 total = 0
    for i = 1 to 12 { total = total + i }
    What is total at the end?
  31. 31.🔁 repeat 5 times { repeat 5 times { beep } }
    How many beeps are there?
  32. 32.🔁 count = 3
    while (count < 35) { count = count + 4 }
    How many times does the loop run?
  33. 33.🔁 repeat 2 times { repeat 5 times { beep } }
    How many beeps are there?
  34. 34.🔁 count = 3
    while (count < 31) { count = count + 4 }
    How many times does the loop run?
  35. 35.🔁 count = 6
    repeat 10 times { count = count + 5 }
    What is count at the end?
  36. 36.🔁 count = 0
    while (count < 40) { count = count + 5 }
    How many times does the loop run?
  37. 37.🔁 count = 5
    repeat 7 times { count = count + 7 }
    What is count at the end?
  38. 38.🔁 count = 1
    repeat 5 times { count = count + 6 }
    What is count at the end?
  39. 39.🔁 repeat 4 times { repeat 5 times { beep } }
    How many beeps are there?
  40. 40.🔁 count = 4
    while (count < 19) { count = count + 5 }
    How many times does the loop run?

Answer key

  1. 3
  2. stores a value
  3. 4
  4. 26
  5. 28
  6. 6
  7. 66
  8. 8
  9. 13
  10. 32
  11. 80
  12. 24
  13. 16
  14. 8
  15. 54
  16. 64
  17. 12
  18. 16
  19. 9
  20. 36
  21. adds 1 to count
  22. 27
  23. 6
  24. 2
  25. 160
  26. 7
  27. 10
  28. 5
  29. 15
  30. 78
  31. 25
  32. 8
  33. 10
  34. 7
  35. 56
  36. 8
  37. 54
  38. 31
  39. 20
  40. 3

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