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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 38 · 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 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) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  2. 2.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 67. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 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
  4. 4.🔦 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 black line (b) the white floor
  5. 5.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor
  6. 6.🔦 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) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  7. 7.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) under the right sensor (d) far behind it
  8. 8.⬛ 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
  9. 9.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 14. What is under the sensor? (a) the white floor (b) the black line
  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 48. What is under the sensor? (a) the black line (b) the white floor
  16. 16.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black soaks up light (d) black is hot
  17. 17.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  23. 23.🔦 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) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  25. 25.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 45. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 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
  27. 27.🔦 A light sensor reads 40 over black and 60 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 75 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  29. 29.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor
  30. 30.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 32. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  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 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
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  36. 36.🔦 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 black line (b) the white floor
  37. 37.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 A light sensor reads 10 over black and 80 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 15 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor

Answer key

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

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