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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 981 · 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 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
  2. 2.🔦 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 right sensor (c) both sensors (d) the left sensor
  3. 3.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the black/white cut-off (d) the wheel size
  4. 4.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  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 below 30 over a black line and above 30 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  11. 11.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is hot (c) black is loud (d) black is wet
  12. 12.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 30. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 22. 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) between the two sensors (b) under the left sensor (c) far behind it (d) under the right sensor
  15. 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 71. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 71. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 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 black line (b) the white floor
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 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
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 57. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 63. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  23. 23.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  25. 25.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
  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 80. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  27. 27.🔦 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 white floor (b) the black line
  28. 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 34. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  31. 31.🔦 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 white floor (b) the black line
  32. 32.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  34. 34.🔦 A light sensor reads 30 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 50. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 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
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  38. 38.🔦 A light sensor reads 20 over black and 90 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 40. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  40. 40.🔦 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 black line (b) the white floor

Answer key

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

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