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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 506 · 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 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 61. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
  5. 5.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 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 black line (b) the white floor
  7. 7.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 23. What is under the sensor? (a) the white floor (b) the black line
  8. 8.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is loud (c) black is wet (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 95 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  11. 11.🔦 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
  12. 12.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the top speed (c) the battery size (d) the wheel size
  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.⬛ 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
  15. 15.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) the sky (d) water
  16. 16.🔦 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) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  18. 18.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  21. 21.🔦 A light sensor reads 20 over black and 80 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 10. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 56. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 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
  25. 25.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 95. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  28. 28.🔦 A light sensor reads 10 over black and 90 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 15 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
  30. 30.🔦 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 white floor (b) the black line
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right 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 20. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  33. 33.🔦 A light sensor reads 10 over black and 80 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 35. What is under the sensor? (a) the white floor (b) the black line
  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 80. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  37. 37.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  38. 38.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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