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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 67 · 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 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 15. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 54. What is under the sensor? (a) the white floor (b) the black line
  4. 4.⬛ 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
  5. 5.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 83. What is under the sensor? (a) the white floor (b) the black line
  8. 8.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 64. What is under the sensor? (a) the white floor (b) the black line
  9. 9.⬛ The threshold of a light sensor is … (a) the top speed (b) the wheel size (c) the black/white cut-off (d) the battery size
  10. 10.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 66. What is under the sensor? (a) the white floor (b) the black line
  11. 11.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  13. 13.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 8. 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 90 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  16. 16.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is wet (c) black soaks up light (d) black is loud
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  25. 25.🔦 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 black line (b) the white floor
  26. 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 50. 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 10 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
  28. 28.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 51. 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 66. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  35. 35.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  36. 36.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) black (d) water
  37. 37.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 80. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 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) the right sensor (b) neither sensor (c) the left sensor (d) both sensors

Answer key

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

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