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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 622 · 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 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 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 black line (b) the white floor
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  4. 4.⬛ 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
  5. 5.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) between the two sensors (c) under the left sensor (d) far behind it
  6. 6.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) white (d) the sky
  7. 7.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 11. What is under the sensor? (a) the white floor (b) the black line
  8. 8.🔦 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) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  10. 10.🔦 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 white floor (b) the black line
  11. 11.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads 10 over black and 60 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 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 20. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 35. What is under the sensor? (a) the black line (b) the white floor
  18. 18.⬛ 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
  19. 19.🔦 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 black line (b) the white floor
  20. 20.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 70. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  25. 25.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 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
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 13. 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 60 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  29. 29.🔦 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 white floor (b) the black line
  30. 30.🔦 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
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  32. 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  34. 34.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 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
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 90. 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 10 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  39. 39.🔦 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
  40. 40.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?

Answer key

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

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