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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 84 · 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 53. 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 55. 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 26. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 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 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 42. What is under the sensor? (a) the black line (b) the white floor
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 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
  8. 8.🔦 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) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  9. 9.🔦 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 black line (b) the white floor
  10. 10.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A light sensor reads 10 over black and 80 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 65. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  13. 13.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) between the two sensors (c) under the left sensor (d) under the right sensor
  14. 14.⬛ The threshold of a light sensor is … (a) the top speed (b) the wheel size (c) the black/white cut-off (d) the battery size
  15. 15.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) black (d) white
  16. 16.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 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
  18. 18.🔦 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
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 26. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 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 black line (b) the white floor
  21. 21.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor
  23. 23.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  24. 24.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black is wet (d) black soaks up light
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  27. 27.🔦 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
  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 75. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  29. 29.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 83. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 12. 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 70 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  35. 35.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 45. 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 white floor (b) the black line
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  38. 38.🔦 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
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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