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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 416 · 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.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) between the two sensors (d) under the right sensor
  2. 2.🔦 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 black line (b) the white floor
  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.🔦 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 white floor (b) the black line
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  8. 8.🔦 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
  9. 9.⬛ The threshold of a light sensor is … (a) the wheel size (b) the top speed (c) the black/white cut-off (d) the battery size
  10. 10.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. 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 41. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  16. 16.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) water (d) white
  17. 17.🔦 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
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 60. 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 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black is hot (d) black soaks up light
  22. 22.🔦 A light sensor reads 10 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 65 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
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 29. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  27. 27.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 46. 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 25 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  29. 29.🔦 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) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  33. 33.🔦 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
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  35. 35.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 18. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 68. 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 95 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  38. 38.🔦 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) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor

Answer key

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

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