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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 123 · 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.⬛ 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
  3. 3.🔦 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 white floor (b) the black line
  4. 4.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  5. 5.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  6. 6.⬛ The threshold of a light sensor is … (a) the top speed (b) the wheel size (c) the battery size (d) the black/white cut-off
  7. 7.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  9. 9.⬛ A reading below the threshold means the sensor is over … (a) white (b) black (c) water (d) the sky
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  11. 11.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 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 black line (b) the white floor
  13. 13.⬛ 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
  14. 14.🔦 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 white floor (b) the black line
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  16. 16.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 59. What is under the sensor? (a) the white floor (b) the black line
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  19. 19.🔦 A light sensor reads 30 over black and 80 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 52. 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 60 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  22. 22.🔦 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 white floor (b) the black line
  23. 23.🔦 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
  24. 24.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 6. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 32. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 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 black line (b) the white floor
  28. 28.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  32. 32.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 70. 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 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
  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 black line (b) the white floor
  36. 36.🔦 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) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  37. 37.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A light sensor reads 40 over black and 70 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 15. 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. between the two sensors
  3. the black line
  4. the white floor
  5. 60
  6. the black/white cut-off
  7. 40
  8. 50
  9. black
  10. neither sensor
  11. the white floor
  12. the white floor
  13. black soaks up light
  14. the black line
  15. the left sensor
  16. 45
  17. the white floor
  18. both sensors
  19. 55
  20. the black line
  21. neither sensor
  22. the white floor
  23. the black line
  24. the black line
  25. the black line
  26. the black line
  27. the black line
  28. 55
  29. 50
  30. the left sensor
  31. both sensors
  32. the black line
  33. the left sensor
  34. the white floor
  35. the white floor
  36. neither sensor
  37. 45
  38. the black line
  39. 55
  40. the right sensor

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