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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 3 · 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 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 20. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 68. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 54. What is under the sensor? (a) the white floor (b) the black line
  5. 5.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) between the two sensors (d) under the left sensor
  6. 6.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  8. 8.⬛ A reading below the threshold means the sensor is over … (a) black (b) water (c) white (d) the sky
  9. 9.🔦 A light sensor reads 20 over black and 60 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 90. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  11. 11.🔦 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 black line (b) the white floor
  12. 12.🔦 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
  13. 13.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  14. 14.⬛ The threshold of a light sensor is … (a) the wheel size (b) the top speed (c) the battery size (d) the black/white cut-off
  15. 15.🔦 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 left sensor (c) the right sensor (d) both sensors
  16. 16.🔦 A light sensor reads 30 over black and 60 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 wet (c) black is loud (d) black is hot
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  20. 20.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 48. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 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 white floor (b) the black line
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  28. 28.🔦 A light sensor reads 40 over black and 80 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 20 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  32. 32.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 85. 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 57. 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 85. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  35. 35.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 64. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 39. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 24. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 20. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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