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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 928 · 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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  2. 2.🔦 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 black line (b) the white floor
  3. 3.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 24. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ 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
  6. 6.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  9. 9.🔦 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
  10. 10.🔦 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
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  12. 12.🔦 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 white floor (b) the black line
  13. 13.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 50. 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 35. What is under the sensor? (a) the white floor (b) the black line
  18. 18.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  20. 20.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black is hot (d) black soaks up light
  21. 21.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) water (d) white
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 60. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 66. What is under the sensor? (a) the white floor (b) the black line
  24. 24.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) far behind it (c) between the two sensors (d) under the left sensor
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 59. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 15. 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 25 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (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 72. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 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
  36. 36.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 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) neither sensor (c) the right sensor (d) the left sensor
  38. 38.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. 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 61. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 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

Answer key

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

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