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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 133 · 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 70 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 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
  3. 3.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 16. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  5. 5.🔦 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) both sensors (b) the left sensor (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 35 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  7. 7.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the top speed (c) the wheel size (d) the battery size
  8. 8.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. What is under the sensor? (a) the black line (b) the white floor
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  10. 10.⬛ 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
  11. 11.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 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) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  13. 13.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 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 white floor (b) the black line
  15. 15.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) the sky (d) water
  16. 16.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 81. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 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
  20. 20.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 26. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 5. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 40. 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 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
  24. 24.🔦 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) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  25. 25.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 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) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 7. What is under the sensor? (a) the white floor (b) the black line
  30. 30.🔦 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
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 59. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 43. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads 10 over black and 70 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 34. 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 60 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  36. 36.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) between the two sensors (d) far behind it
  37. 37.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 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
  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 10. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor

Answer key

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

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