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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 953 · 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 below 50 over a black line and above 50 over the white floor. It reads 58. What is under the sensor? (a) the white floor (b) the black line
  2. 2.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 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) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  4. 4.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  6. 6.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) under the left sensor (c) far behind it (d) under the right sensor
  7. 7.🔦 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 white floor (b) the black line
  8. 8.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  10. 10.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 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 white floor (b) the black line
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  13. 13.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is wet (d) black is hot
  14. 14.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 48. What is under the sensor? (a) the white floor (b) the black line
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 16. What is under the sensor? (a) the white floor (b) the black line
  17. 17.🔦 A light sensor reads 40 over black and 70 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 75 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
  19. 19.🔦 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 right sensor (b) neither sensor (c) both sensors (d) the left sensor
  20. 20.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 77. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 13. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  23. 23.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  25. 25.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the wheel size (d) the black/white cut-off
  26. 26.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 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 black line (b) the white floor
  33. 33.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  34. 34.🔦 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 right sensor (b) the left sensor (c) both sensors (d) neither sensor
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  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 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  37. 37.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  38. 38.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 43. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 69. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 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

Answer key

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

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