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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 457 · 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 light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  5. 5.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 53. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  8. 8.🔦 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
  9. 9.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  10. 10.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 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 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 15 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
  13. 13.🔦 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 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 80 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 16. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  18. 18.⬛ A reading below the threshold means the sensor is over … (a) black (b) the sky (c) white (d) water
  19. 19.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is hot (d) black is wet
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  21. 21.🔦 A light sensor reads 20 over black and 60 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 42. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  24. 24.🔦 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 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 32. 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 63. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 62. 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 90 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  29. 29.⬛ 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
  30. 30.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) far behind it (d) between the two sensors
  31. 31.🔦 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
  32. 32.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  34. 34.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 64. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  36. 36.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 62. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  40. 40.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?

Answer key

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

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