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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 285 · 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 30 over a black line and above 30 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
  2. 2.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) under the right sensor (c) far behind it (d) between the two sensors
  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.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the wheel size (c) the top speed (d) the battery size
  5. 5.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  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 60. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  8. 8.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  9. 9.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) the sky (d) white
  10. 10.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  12. 12.🔦 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
  13. 13.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 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
  15. 15.🔦 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 white floor (b) the black line
  16. 16.🔦 A light sensor reads below 30 over a black line and above 30 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 50 over a black line and above 50 over the white floor. It reads 59. What is under the sensor? (a) the white floor (b) the black line
  18. 18.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is hot (c) black is loud (d) black soaks up light
  19. 19.🔦 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 white floor (b) the black line
  20. 20.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  22. 22.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 71. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 70. 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 60 over a black line and above 60 over the white floor. It reads 78. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 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
  27. 27.🔦 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
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  29. 29.🔦 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
  30. 30.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 15. 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 10 and the right sensor reads 40. 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 below 40 over a black line and above 40 over the white floor. It reads 22. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 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
  36. 36.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 61. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 67. 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 85 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  40. 40.🔦 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

Answer key

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

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