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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 262 · 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 80 over white. A good threshold is halfway between them. What is it?
  2. 2.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the black/white cut-off (d) the top speed
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  4. 4.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  8. 8.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) water (d) black
  9. 9.🔦 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) the right sensor (d) neither sensor
  10. 10.🔦 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
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  12. 12.🔦 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) neither sensor (c) the left sensor (d) both sensors
  13. 13.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 76. What is under the sensor? (a) the white floor (b) the black line
  15. 15.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  16. 16.🔦 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 black line (b) the white floor
  17. 17.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
  19. 19.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is hot (c) black soaks up light (d) black is wet
  20. 20.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 14. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 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
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 17. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 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
  26. 26.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 80. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 74. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 49. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  30. 30.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
  31. 31.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) between the two sensors (d) under the left sensor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  33. 33.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 17. 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 70 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  36. 36.🔦 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) the left sensor (c) neither sensor (d) the right sensor
  37. 37.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 90. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor

Answer key

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

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