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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 795 · 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 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  3. 3.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ 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
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  6. 6.⬛ 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 loud (d) black is hot
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 74. What is under the sensor? (a) the black line (b) the white floor
  8. 8.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) far behind it (c) under the left sensor (d) under the right sensor
  9. 9.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) black (d) water
  10. 10.🔦 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
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  12. 12.🔦 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 white floor (b) the black line
  13. 13.🔦 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
  14. 14.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 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
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
  17. 17.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 29. What is under the sensor? (a) the white floor (b) the black line
  18. 18.🔦 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 black line (b) the white floor
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  20. 20.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 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 white floor (b) the black line
  22. 22.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 39. What is under the sensor? (a) the white floor (b) the black line
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  26. 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 16. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 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
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 68. 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 85 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  30. 30.🔦 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 white floor (b) the black line
  31. 31.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 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) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  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 65. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  34. 34.🔦 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
  35. 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 56. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  38. 38.🔦 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) the right sensor (c) the left sensor (d) both sensors
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?

Answer key

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

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