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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 445 · 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 40 over a black line and above 40 over the white floor. It reads 43. What is under the sensor? (a) the white floor (b) the black line
  2. 2.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  3. 3.⬛ 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 loud (d) black is wet
  4. 4.⬛ The threshold of a light sensor is … (a) the top speed (b) the black/white cut-off (c) the battery size (d) the wheel size
  5. 5.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  6. 6.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) under the left sensor (d) between the two sensors
  7. 7.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  8. 8.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) white (d) water
  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 80. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  10. 10.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 26. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  12. 12.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 71. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 39. 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 75 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  18. 18.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 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
  20. 20.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 66. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 48. What is under the sensor? (a) the black line (b) the white floor
  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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  28. 28.🔦 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 right sensor (b) neither sensor (c) both sensors (d) the left sensor
  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 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  30. 30.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads 30 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 35 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  35. 35.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 22. 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 65 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  38. 38.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 23. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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