← Loops and variables lesson New set →

Electronics Worksheet: Loops and Variables

Electronics lesson 25: Loops and variables · Set 869 · 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 a variable do in a program? (a) joins two wires (b) blinks an LED (c) measures light (d) stores a value
  2. 2.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
  3. 3.🔁 count = 4
    while (count < 16) { count = count + 3 }
    How many times does the loop run?
  4. 4.🔁 repeat 3 times { repeat 2 times { beep } }
    How many beeps are there?
  5. 5.🔁 count = 0
    while (count < 24) { count = count + 3 }
    How many times does the loop run?
  6. 6.🔁 x = 2
    repeat 5 times { x = x × 2 }
    What is x at the end?
  7. 7.🔁 total = 0
    for i = 1 to 11 { total = total + i }
    What is total at the end?
  8. 8.🔁 x = 2
    repeat 1 time { x = x × 2 }
    What is x at the end?
  9. 9.🔁 repeat 2 times { repeat 3 times { beep } }
    How many beeps are there?
  10. 10.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
  11. 11.🔁 count = 3
    while (count < 19) { count = count + 2 }
    How many times does the loop run?
  12. 12.🔁 count = 4
    while (count < 39) { count = count + 5 }
    How many times does the loop run?
  13. 13.🔁 count = 1
    while (count < 7) { count = count + 3 }
    How many times does the loop run?
  14. 14.🔁 repeat 4 times { repeat 5 times { beep } }
    How many beeps are there?
  15. 15.🔁 count = 1
    while (count < 25) { count = count + 3 }
    How many times does the loop run?
  16. 16.🔁 count = 2
    repeat 3 times { count = count + 10 }
    What is count at the end?
  17. 17.🔁 count = 3
    while (count < 18) { count = count + 3 }
    How many times does the loop run?
  18. 18.🔁 repeat 2 times { repeat 5 times { beep } }
    How many beeps are there?
  19. 19.🔁 count = 10
    repeat 4 times { count = count + 4 }
    What is count at the end?
  20. 20.🔁 repeat 2 times { repeat 4 times { beep } }
    How many beeps are there?
  21. 21.🔁 count = 1
    repeat 3 times { count = count + 4 }
    What is count at the end?
  22. 22.🔁 What does “count = count + 1” do? (a) takes 1 away (b) adds 1 to count (c) prints 1 (d) sets count to 1
  23. 23.🔁 x = 1
    repeat 3 times { x = x × 2 }
    What is x at the end?
  24. 24.🔁 count = 4
    repeat 4 times { count = count + 5 }
    What is count at the end?
  25. 25.🔁 total = 0
    for i = 1 to 9 { total = total + i }
    What is total at the end?
  26. 26.🔁 x = 5
    repeat 3 times { x = x × 2 }
    What is x at the end?
  27. 27.🔁 repeat 3 times { repeat 4 times { beep } }
    How many beeps are there?
  28. 28.🔁 x = 3
    repeat 3 times { x = x × 2 }
    What is x at the end?
  29. 29.🔁 count = 2
    repeat 5 times { count = count + 8 }
    What is count at the end?
  30. 30.🔁 total = 0
    for i = 1 to 12 { total = total + i }
    What is total at the end?
  31. 31.🔁 x = 4
    repeat 4 times { x = x × 2 }
    What is x at the end?
  32. 32.🔁 count = 2
    repeat 6 times { count = count + 9 }
    What is count at the end?
  33. 33.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
  34. 34.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
  35. 35.🔁 count = 1
    repeat 7 times { count = count + 9 }
    What is count at the end?
  36. 36.🔁 count = 0
    while (count < 12) { count = count + 3 }
    How many times does the loop run?
  37. 37.🔁 repeat 3 times { repeat 5 times { beep } }
    How many beeps are there?
  38. 38.🔁 count = 10
    repeat 4 times { count = count + 3 }
    What is count at the end?
  39. 39.🔁 x = 3
    repeat 2 times { x = x × 2 }
    What is x at the end?
  40. 40.🔁 count = 0
    repeat 8 times { count = count + 9 }
    What is count at the end?

Answer key

  1. stores a value
  2. 4
  3. 4
  4. 6
  5. 8
  6. 64
  7. 66
  8. 4
  9. 6
  10. 15
  11. 8
  12. 7
  13. 2
  14. 20
  15. 8
  16. 32
  17. 5
  18. 10
  19. 26
  20. 8
  21. 13
  22. adds 1 to count
  23. 8
  24. 24
  25. 45
  26. 40
  27. 12
  28. 24
  29. 42
  30. 78
  31. 64
  32. 56
  33. 21
  34. 16
  35. 64
  36. 4
  37. 15
  38. 22
  39. 12
  40. 72

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