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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 360 · 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 reading below the threshold means the sensor is over … (a) water (b) white (c) black (d) the sky
  2. 2.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the wheel size (d) the black/white cut-off
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 35. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 39. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 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
  7. 7.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 12. What is under the sensor? (a) the black line (b) the white floor
  8. 8.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black soaks up light (d) black is hot
  9. 9.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  11. 11.🔦 A light sensor reads 30 over black and 80 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 35 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  13. 13.🔦 A light sensor reads 30 over black and 90 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 35. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  16. 16.🔦 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
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 77. 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 20 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
  21. 21.🔦 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) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  22. 22.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 56. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  26. 26.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) between the two sensors (c) under the right sensor (d) under the left sensor
  27. 27.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 90. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  31. 31.🔦 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
  32. 32.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  35. 35.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 76. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A light sensor reads 20 over black and 90 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 63. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors

Answer key

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

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