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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 65 · 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 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 41. What is under the sensor? (a) the white floor (b) the black line
  3. 3.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the black/white cut-off (d) the wheel size
  4. 4.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 15. What is under the sensor? (a) the white floor (b) the black line
  5. 5.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  8. 8.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is hot (c) black is loud (d) black soaks up light
  9. 9.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 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 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 20 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  13. 13.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. 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 35 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  15. 15.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 5. 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 95 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  17. 17.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) between the two sensors (d) under the right sensor
  18. 18.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 black line (b) the white floor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  22. 22.🔦 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) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  23. 23.🔦 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 black line (b) the white floor
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 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) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 54. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  29. 29.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  31. 31.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) water (c) white (d) black
  32. 32.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 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
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  35. 35.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 70. 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 10 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  39. 39.🔦 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 left sensor (b) both sensors (c) the right sensor (d) neither sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor

Answer key

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

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