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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 381 · 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 60 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 62. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  4. 4.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  6. 6.⬛ The threshold of a light sensor is … (a) the wheel size (b) the battery size (c) the black/white cut-off (d) the top speed
  7. 7.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  8. 8.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is hot (c) black is wet (d) black soaks up light
  9. 9.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  11. 11.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 35. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 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 black line (b) the white floor
  14. 14.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 69. What is under the sensor? (a) the black line (b) the white floor
  16. 16.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) far behind it (c) under the right sensor (d) under the left sensor
  17. 17.🔦 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
  18. 18.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) white (d) the sky
  19. 19.🔦 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 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 79. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 59. 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 75 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 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 black line (b) the white floor
  29. 29.🔦 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 black line (b) the white floor
  30. 30.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 9. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. 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 65. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 70. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  36. 36.🔦 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) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  38. 38.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 29. 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 36. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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