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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 789 · 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 25. What is under the sensor? (a) the white floor (b) the black line
  2. 2.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 49. What is under the sensor? (a) the black line (b) the white floor
  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.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) white (d) water
  5. 5.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) under the right sensor (d) between the two sensors
  6. 6.🔦 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 white floor (b) the black line
  7. 7.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the top speed (c) the wheel size (d) the battery size
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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.⬛ 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
  10. 10.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  15. 15.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 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 black line (b) the white floor
  17. 17.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 51. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 30. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 26. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. What is under the sensor? (a) the black line (b) the white floor
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  24. 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 84. 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 57. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 30 over black and 70 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 20 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  29. 29.🔦 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 white floor (b) the black line
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  31. 31.🔦 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) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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 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) both sensors (c) neither sensor (d) the left sensor
  35. 35.🔦 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) the left sensor (c) both sensors (d) the right sensor
  36. 36.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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