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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 711 · 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 40 over a black line and above 40 over the white floor. It reads 20. What is under the sensor? (a) the white floor (b) the black line
  2. 2.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 36. What is under the sensor? (a) the white floor (b) the black line
  3. 3.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) white (d) black
  4. 4.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  6. 6.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is hot (c) black is wet (d) black is loud
  7. 7.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the black/white cut-off (d) the wheel size
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  9. 9.🔦 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
  10. 10.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 49. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 A light sensor reads 20 over black and 80 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 80. What is under the sensor? (a) the black line (b) the white floor
  14. 14.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 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 white floor (b) the black line
  17. 17.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  20. 20.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 64. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 75. What is under the sensor? (a) the black line (b) the white floor
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 71. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 62. What is under the sensor? (a) the white floor (b) the black line
  25. 25.🔦 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 black line (b) the white floor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  27. 27.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 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 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 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
  31. 31.🔦 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
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right 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 51. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 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 white floor (b) the black line
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. What is under the sensor? (a) the white floor (b) the black line
  37. 37.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) between the two sensors (d) far behind it
  38. 38.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 6. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 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

Answer key

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

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