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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 34 · 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 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  2. 2.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) white (d) water
  3. 3.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 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) neither sensor (c) both sensors (d) the left sensor
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  6. 6.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black soaks up light (c) black is wet (d) black is loud
  7. 7.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 42. What is under the sensor? (a) the black line (b) the white floor
  9. 9.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  10. 10.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the black/white cut-off (d) the top speed
  11. 11.🔦 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
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  13. 13.🔦 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
  14. 14.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) between the two sensors (d) far behind it
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  16. 16.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 29. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 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) the right sensor (c) both sensors (d) the left sensor
  19. 19.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 27. 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 44. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 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
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 43. 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 80 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  25. 25.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 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
  29. 29.🔦 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 black line (b) the white floor
  30. 30.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 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 white floor (b) the black line
  32. 32.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 40. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 34. 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 47. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  36. 36.🔦 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
  37. 37.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  40. 40.🔦 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

Answer key

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

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