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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 31 · 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 50 over a black line and above 50 over the white floor. It reads 56. What is under the sensor? (a) the black line (b) the white floor
  2. 2.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is hot (d) black is wet
  5. 5.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor
  7. 7.🔦 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) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  8. 8.🔦 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 right sensor (b) both sensors (c) neither sensor (d) the left sensor
  9. 9.⬛ 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
  10. 10.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) white (d) black
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  14. 14.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  16. 16.⬛ 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
  17. 17.🔦 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 black line (b) the white floor
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 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) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 32. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 22. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 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
  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 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  27. 27.🔦 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 black line (b) the white floor
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. 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 40 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  30. 30.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 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
  32. 32.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 69. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 59. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  37. 37.🔦 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 white floor (b) the black line
  38. 38.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  40. 40.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 13. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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