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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 273 · 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 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
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 16. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 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 left sensor (b) both sensors (c) the right sensor (d) neither sensor
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  6. 6.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black soaks up light (c) black is loud (d) black is hot
  7. 7.⬛ The threshold of a light sensor is … (a) the wheel size (b) the top speed (c) the black/white cut-off (d) the battery size
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  9. 9.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) far behind it (d) under the right sensor
  10. 10.🔦 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
  11. 11.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 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 right sensor (b) both sensors (c) the left sensor (d) neither sensor
  13. 13.🔦 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 white floor (b) the black line
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 60. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 35. 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 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  17. 17.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) white (d) black
  18. 18.🔦 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 white floor (b) the black line
  19. 19.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  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 white floor (b) the black line
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 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
  22. 22.🔦 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) the left sensor (d) both sensors
  23. 23.🔦 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 black line (b) the white floor
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  30. 30.🔦 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) the right sensor (b) neither sensor (c) both sensors (d) the left 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 15. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  33. 33.🔦 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 white floor (b) the black line
  34. 34.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 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
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  37. 37.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  39. 39.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 50. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?

Answer key

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

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