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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 728 · 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 40 over a black line and above 40 over the white floor. It reads 31. What is under the sensor? (a) the black line (b) the white floor
  2. 2.🔦 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
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  5. 5.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 58. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  7. 7.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  11. 11.⬛ A reading below the threshold means the sensor is over … (a) white (b) water (c) black (d) the sky
  12. 12.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
  15. 15.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads 10 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 21. What is under the sensor? (a) the white floor (b) the black line
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  20. 20.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  22. 22.⬛ 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
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  24. 24.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 33. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  28. 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 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) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  30. 30.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 28. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 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
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 48. What is under the sensor? (a) the black line (b) the white floor
  35. 35.⬛ 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
  36. 36.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 57. What is under the sensor? (a) the black line (b) the white floor
  38. 38.🔦 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 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 70 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  40. 40.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the black/white cut-off (d) the wheel size

Answer key

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

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