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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 325 · 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 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the black/white cut-off (d) the wheel size
  5. 5.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) between the two sensors (d) under the left sensor
  6. 6.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black is wet (d) black soaks up light
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  8. 8.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 84. 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 48. What is under the sensor? (a) the white floor (b) the black line
  10. 10.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 33. 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 40 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
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 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
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 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
  15. 15.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 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
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  23. 23.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  24. 24.⬛ A reading below the threshold means the sensor is over … (a) white (b) black (c) water (d) the sky
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 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 white floor (b) the black line
  28. 28.🔦 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 white floor (b) the black line
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  30. 30.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 12. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 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) neither sensor (d) the left sensor
  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 40. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  34. 34.🔦 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
  35. 35.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  37. 37.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 59. 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 90 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  39. 39.🔦 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
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 10. 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. 50
  3. 35
  4. the black/white cut-off
  5. between the two sensors
  6. black soaks up light
  7. the left sensor
  8. the white floor
  9. the white floor
  10. 45
  11. the black line
  12. the left sensor
  13. neither sensor
  14. the right sensor
  15. 55
  16. the left sensor
  17. the black line
  18. 60
  19. the white floor
  20. the left sensor
  21. both sensors
  22. both sensors
  23. 60
  24. black
  25. the left sensor
  26. the black line
  27. the black line
  28. the white floor
  29. the white floor
  30. the black line
  31. the black line
  32. the right sensor
  33. both sensors
  34. the white floor
  35. 40
  36. both sensors
  37. the white floor
  38. the right sensor
  39. the black line
  40. both sensors

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