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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 352 · 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.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black is wet (d) black soaks up light
  2. 2.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  3. 3.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) the sky (d) white
  4. 4.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) between the two sensors (d) far behind it
  5. 5.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  10. 10.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 82. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  13. 13.🔦 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) neither sensor (c) the left sensor (d) the right sensor
  14. 14.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.⬛ 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
  18. 18.🔦 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) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  19. 19.🔦 A light sensor reads 10 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 10 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  21. 21.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 49. What is under the sensor? (a) the black line (b) the white floor
  23. 23.🔦 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
  24. 24.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 11. 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 74. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 43. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 31. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  30. 30.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 75. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads 20 over black and 60 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 75 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  33. 33.🔦 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
  34. 34.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 44. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
  38. 38.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A light sensor reads 40 over black and 90 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 25 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor

Answer key

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

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