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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 121 · 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 60 over a black line and above 60 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  2. 2.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 37. What is under the sensor? (a) the white floor (b) the black line
  3. 3.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) black (d) water
  4. 4.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black soaks up light (c) black is hot (d) black is loud
  6. 6.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) far behind it (c) between the two sensors (d) under the left sensor
  7. 7.🔦 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 black line (b) the white floor
  8. 8.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 26. What is under the sensor? (a) the white floor (b) the black line
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 25. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  10. 10.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the wheel size (d) the black/white cut-off
  11. 11.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 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
  13. 13.🔦 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
  14. 14.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 32. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 90. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  18. 18.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads 20 over black and 70 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 31. 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 35. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 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
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  26. 26.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  30. 30.🔦 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 black line (b) the white floor
  31. 31.🔦 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) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  32. 32.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 63. What is under the sensor? (a) the black line (b) the white floor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 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
  34. 34.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  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 20. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  36. 36.🔦 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 left sensor (b) the right sensor (c) neither sensor (d) both sensors
  37. 37.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  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 80 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors

Answer key

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

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