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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 33 · 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 53. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 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 white floor (b) the black line
  4. 4.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black soaks up light (d) black is hot
  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 light sensor reads below 60 over a black line and above 60 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  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 20. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  8. 8.⬛ A reading below the threshold means the sensor is over … (a) white (b) water (c) the sky (d) black
  9. 9.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  11. 11.⬛ 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
  12. 12.🔦 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
  13. 13.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 45. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 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
  16. 16.🔦 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) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  17. 17.🔦 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
  18. 18.🔦 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
  19. 19.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  20. 20.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) between the two sensors (c) under the left sensor (d) under the right sensor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 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
  22. 22.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 49. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 67. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  27. 27.🔦 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 black line (b) the white floor
  28. 28.🔦 A light sensor reads 30 over black and 60 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 75 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  30. 30.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 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
  33. 33.🔦 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) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  34. 34.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  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 85. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  37. 37.🔦 A light sensor reads below 60 over a black line and above 60 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 below 60 over a black line and above 60 over the white floor. It reads 53. 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 15 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor

Answer key

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

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