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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 17 · 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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  3. 3.⬛ The threshold of a light sensor is … (a) the top speed (b) the black/white cut-off (c) the wheel size (d) the battery size
  4. 4.🔦 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
  5. 5.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  7. 7.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is hot (c) black soaks up light (d) black is loud
  8. 8.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  11. 11.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) the sky (d) white
  12. 12.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  13. 13.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 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
  15. 15.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) under the right sensor (d) between the two sensors
  16. 16.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 45. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  18. 18.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 64. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 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 black line (b) the white floor
  21. 21.🔦 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 white floor (b) the black line
  22. 22.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 43. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 65. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  25. 25.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 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
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  29. 29.🔦 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 black line (b) the white floor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  33. 33.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 71. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  35. 35.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 22. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 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
  37. 37.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 37. What is under the sensor? (a) the white floor (b) the black line
  38. 38.🔦 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 white floor (b) the black line
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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