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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 36 · 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.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the wheel size (d) the black/white cut-off
  2. 2.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads 40 over black and 60 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 soaks up light (c) black is wet (d) black is loud
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  6. 6.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  8. 8.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  10. 10.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 61. What is under the sensor? (a) the white floor (b) the black line
  11. 11.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 34. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 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
  14. 14.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 61. What is under the sensor? (a) the white floor (b) the black line
  15. 15.🔦 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 black line (b) the white floor
  16. 16.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) under the right sensor (d) far behind it
  17. 17.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 52. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  26. 26.🔦 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 black line (b) the white floor
  27. 27.🔦 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 white floor (b) the black line
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  31. 31.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads 20 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 60 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 52. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  38. 38.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 26. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  40. 40.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?

Answer key

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

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