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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 44 · 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 90 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  3. 3.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black soaks up light (d) black is wet
  4. 4.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 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
  7. 7.🔦 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
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 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
  9. 9.⬛ The threshold of a light sensor is … (a) the battery size (b) the black/white cut-off (c) the top speed (d) the wheel size
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  11. 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  13. 13.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) between the two sensors (c) far behind it (d) under the left sensor
  14. 14.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 74. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 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) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) white (d) water
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  22. 22.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 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 black line (b) the white floor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  27. 27.🔦 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
  28. 28.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  30. 30.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 60. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 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
  33. 33.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 24. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 62. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 61. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  37. 37.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 75. What is under the sensor? (a) the black line (b) the white floor
  38. 38.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor

Answer key

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

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