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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 365 · 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 80 over white. A good threshold is halfway between them. What is it?
  2. 2.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) under the right sensor (d) between the two sensors
  3. 3.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  5. 5.🔦 A light sensor reads 40 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 38. What is under the sensor? (a) the white floor (b) the black line
  7. 7.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black is hot (d) black soaks up light
  8. 8.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 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 white floor (b) the black line
  10. 10.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the top speed (d) the black/white cut-off
  11. 11.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  12. 12.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) water (c) white (d) black
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  14. 14.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  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 white floor (b) the black line
  17. 17.🔦 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 left sensor (b) both sensors (c) neither sensor (d) the right sensor
  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 75. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 95. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  22. 22.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
  26. 26.🔦 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 white floor (b) the black line
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 37. 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 75 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 49. What is under the sensor? (a) the black line (b) the white floor
  30. 30.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads 20 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 60 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  33. 33.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 21. 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 25 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  35. 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 73. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 76. What is under the sensor? (a) the black line (b) the white floor
  38. 38.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 8. 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 47. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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