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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 48 · 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 below 30 over a black line and above 30 over the white floor. It reads 44. What is under the sensor? (a) the black line (b) the white floor
  2. 2.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 48. What is under the sensor? (a) the white floor (b) the black line
  4. 4.⬛ A reading below the threshold means the sensor is over … (a) black (b) the sky (c) water (d) white
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 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
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  7. 7.🔦 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 black line (b) the white floor
  8. 8.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 73. What is under the sensor? (a) the white floor (b) the black line
  11. 11.🔦 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
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  14. 14.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  16. 16.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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 black line (b) the white floor
  18. 18.⬛ The threshold of a light sensor is … (a) the battery size (b) the black/white cut-off (c) the wheel size (d) the top speed
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  20. 20.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is wet (c) black is loud (d) black soaks up light
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 52. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 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
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 18. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 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 black line (b) the white floor
  28. 28.🔦 A light sensor reads 40 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 25 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
  30. 30.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) far behind it (c) under the left sensor (d) under the right sensor
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 64. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 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) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  33. 33.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 30. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  37. 37.🔦 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
  38. 38.🔦 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 black line (b) the white floor
  39. 39.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors

Answer key

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

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