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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 5 · 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.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black soaks up light (c) black is hot (d) black is loud
  2. 2.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  3. 3.⬛ The threshold of a light sensor is … (a) the top speed (b) the black/white cut-off (c) the wheel size (d) the battery size
  4. 4.🔦 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
  5. 5.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) water (d) black
  6. 6.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 73. What is under the sensor? (a) the black line (b) the white floor
  7. 7.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 30. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (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 26. What is under the sensor? (a) the black line (b) the white floor
  10. 10.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) between the two sensors (d) under the right sensor
  11. 11.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 65. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 32. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  17. 17.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  19. 19.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 26. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  22. 22.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 67. What is under the sensor? (a) the white floor (b) the black line
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 64. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  30. 30.🔦 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
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  34. 34.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 11. What is under the sensor? (a) the white floor (b) the black line
  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 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  38. 38.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 59. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 14. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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