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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 491 · 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.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 69. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 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
  4. 4.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  6. 6.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 42. What is under the sensor? (a) the black line (b) the white floor
  7. 7.🔦 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
  8. 8.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 75. What is under the sensor? (a) the white floor (b) the black line
  9. 9.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. What is under the sensor? (a) the white floor (b) the black line
  10. 10.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  11. 11.⬛ The threshold of a light sensor is … (a) the battery size (b) the black/white cut-off (c) the wheel size (d) the top speed
  12. 12.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) black (d) white
  13. 13.🔦 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) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  14. 14.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  18. 18.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 39. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 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 black line (b) the white floor
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  23. 23.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 61. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
  26. 26.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) under the right sensor (d) far behind it
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  30. 30.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 15. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  33. 33.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  34. 34.⬛ 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 wet (d) black is loud
  35. 35.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 51. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 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
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. What is under the sensor? (a) the white floor (b) the black line

Answer key

  1. 45
  2. the white floor
  3. the black line
  4. 55
  5. the right sensor
  6. the black line
  7. the black line
  8. the white floor
  9. the black line
  10. 45
  11. the black/white cut-off
  12. black
  13. the left sensor
  14. 50
  15. the black line
  16. the right sensor
  17. the right sensor
  18. 50
  19. the left sensor
  20. the black line
  21. the black line
  22. the left sensor
  23. 60
  24. the white floor
  25. the white floor
  26. between the two sensors
  27. the white floor
  28. the white floor
  29. the right sensor
  30. 35
  31. both sensors
  32. the left sensor
  33. 60
  34. black soaks up light
  35. 40
  36. the black line
  37. the white floor
  38. both sensors
  39. the black line
  40. the white floor

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