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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 308 · 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 67. 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 35 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  3. 3.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 84. What is under the sensor? (a) the white floor (b) the black line
  4. 4.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
  5. 5.⬛ The threshold of a light sensor is … (a) the wheel size (b) the battery size (c) the top speed (d) the black/white cut-off
  6. 6.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  7. 7.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) between the two sensors (c) under the right sensor (d) under the left sensor
  8. 8.🔦 A light sensor reads 10 over black and 70 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 25 and the right sensor reads 85. 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 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 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 white floor (b) the black line
  12. 12.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 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 black line (b) the white floor
  14. 14.🔦 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
  15. 15.⬛ 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 loud (d) black is wet
  16. 16.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  17. 17.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 19. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 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) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  20. 20.🔦 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
  21. 21.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 7. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 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 white floor (b) the black line
  23. 23.🔦 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
  24. 24.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 35. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A light sensor reads 10 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 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  30. 30.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 42. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  33. 33.🔦 A light sensor reads 20 over black and 70 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 80 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  35. 35.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 24. 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 10. 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 65. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 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
  39. 39.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor

Answer key

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

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