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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 317 · 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 60 over a black line and above 60 over the white floor. It reads 71. What is under the sensor? (a) the black line (b) the white floor
  2. 2.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the wheel size (d) the black/white cut-off
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  4. 4.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) under the left sensor (d) between the two sensors
  6. 6.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
  7. 7.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 81. What is under the sensor? (a) the white floor (b) the black line
  9. 9.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 30. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 95. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  11. 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 79. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  14. 14.🔦 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) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  17. 17.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 17. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 26. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  21. 21.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A light sensor reads 40 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 75. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither 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 26. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 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
  26. 26.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  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 60. Which sensor is over the black line? (a) neither sensor (b) the right 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 30 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  30. 30.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  31. 31.⬛ 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
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 16. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  34. 34.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  36. 36.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 39. What is under the sensor? (a) the black line (b) the white floor
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  39. 39.🔦 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) the right sensor (b) both sensors (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 9. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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