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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 72 · 40 questions
TalentJR

Robot tip (Below the threshold is black): Reading below the threshold → black; above → white. Threshold = (black reading + white reading) ÷ 2. Two sensors: the one that reads black is over the line; both white → the line is between them.

NameDateTime takenScore ___ / 40
  1. 1.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 66. What is under the sensor? (a) the white floor (b) the black line
  2. 2.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black soaks up light (d) black is wet
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  6. 6.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the top speed (d) the black/white cut-off
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  9. 9.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 24. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 52. What is under the sensor? (a) the white floor (b) the black line
  11. 11.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 18. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 48. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 90. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  15. 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 57. What is under the sensor? (a) the black line (b) the white floor
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  17. 17.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 40. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 45. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  23. 23.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) water (d) white
  24. 24.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  34. 34.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  36. 36.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 76. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor

Answer key

  1. the white floor
  2. 40
  3. 65
  4. black soaks up light
  5. the right sensor
  6. the black/white cut-off
  7. the right sensor
  8. the right sensor
  9. the black line
  10. the black line
  11. the black line
  12. 35
  13. the black line
  14. the left sensor
  15. the white floor
  16. the left sensor
  17. 55
  18. the black line
  19. the white floor
  20. 60
  21. the left sensor
  22. the right sensor
  23. black
  24. 45
  25. 40
  26. the black line
  27. the right sensor
  28. the white floor
  29. 50
  30. 60
  31. neither sensor
  32. neither sensor
  33. the left sensor
  34. 45
  35. both sensors
  36. the white floor
  37. the black line
  38. neither sensor
  39. the left sensor
  40. neither sensor

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