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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 129 · 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.⬛ 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
  2. 2.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black soaks up light (d) black is wet
  3. 3.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  5. 5.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  8. 8.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  10. 10.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the top speed (d) the black/white cut-off
  11. 11.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  13. 13.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) water (d) the sky
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  15. 15.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 63. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  21. 21.🔦 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) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  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 15. 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 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
  24. 24.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 39. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 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
  28. 28.🔦 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
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right 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 61. 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 10. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  32. 32.🔦 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) neither sensor (d) both sensors
  33. 33.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 85. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 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 left sensor (b) neither sensor (c) both sensors (d) the right sensor
  37. 37.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  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 30. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 29. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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