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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 849 · 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.⬛ 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
  2. 2.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) between the two sensors (d) under the right sensor
  3. 3.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 32. What is under the sensor? (a) the black line (b) the white floor
  4. 4.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) water (d) black
  5. 5.🔦 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 black line (b) the white floor
  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 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
  8. 8.🔦 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
  9. 9.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  12. 12.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 6. What is under the sensor? (a) the white floor (b) the black line
  13. 13.🔦 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
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  15. 15.🔦 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 white floor (b) the black line
  16. 16.🔦 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
  17. 17.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  20. 20.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 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 white floor (b) the black line
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 18. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  26. 26.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  28. 28.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is hot (c) black is wet (d) black is loud
  29. 29.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 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 black line (b) the white floor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 10. 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 10 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 16. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (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 75 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  37. 37.🔦 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) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  38. 38.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 69. 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 85 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor

Answer key

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

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