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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 720 · 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 20 over black and 80 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 20 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  3. 3.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 6. What is under the sensor? (a) the white floor (b) the black line
  5. 5.🔦 A light sensor reads 10 over black and 80 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 40 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  7. 7.🔦 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) both sensors (c) neither sensor (d) the right sensor
  8. 8.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black soaks up light (d) black is hot
  9. 9.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) under the left sensor (c) far behind it (d) under the right sensor
  10. 10.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 66. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 56. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  13. 13.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 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
  16. 16.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the black/white cut-off (d) the top speed
  17. 17.⬛ A reading below the threshold means the sensor is over … (a) water (b) white (c) black (d) the sky
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  19. 19.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 71. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 49. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 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 white floor (b) the black line
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  24. 24.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  26. 26.🔦 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
  27. 27.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 15. What is under the sensor? (a) the white floor (b) the black line
  30. 30.🔦 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 right sensor (b) the left sensor (c) both sensors (d) neither sensor
  31. 31.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 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) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 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
  36. 36.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 80. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 47. 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 46. 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 85 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) the right 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 60 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor

Answer key

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

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