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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 203 · 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.⬛ 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
  2. 2.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  3. 3.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  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 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
  6. 6.🔦 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
  7. 7.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 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
  9. 9.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 69. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  12. 12.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 39. What is under the sensor? (a) the white floor (b) the black line
  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 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
  15. 15.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. What is under the sensor? (a) the black line (b) the white floor
  16. 16.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  17. 17.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is loud (c) black is wet (d) black is hot
  18. 18.🔦 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
  19. 19.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 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
  21. 21.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  23. 23.🔦 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 white floor (b) the black line
  24. 24.🔦 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
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 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 black line (b) the white floor
  30. 30.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) far behind it (c) between the two sensors (d) under the left sensor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  32. 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  33. 33.🔦 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
  34. 34.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  35. 35.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) water (d) the sky
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  37. 37.🔦 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 right sensor (b) neither sensor (c) the left sensor (d) both sensors
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 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
  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 40. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors

Answer key

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

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