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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 331 · 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 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
  5. 5.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black soaks up light (d) black is hot
  6. 6.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 20. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 30. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  11. 11.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  13. 13.🔦 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) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  14. 14.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 69. What is under the sensor? (a) the white floor (b) the black line
  15. 15.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the wheel size (d) the black/white cut-off
  16. 16.⬛ A reading below the threshold means the sensor is over … (a) black (b) water (c) white (d) the sky
  17. 17.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 5. What is under the sensor? (a) the white floor (b) the black line
  18. 18.🔦 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
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  20. 20.🔦 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
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 25. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  23. 23.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  24. 24.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) under the right sensor (d) between the two sensors
  25. 25.🔦 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) neither sensor (c) the left sensor (d) the right sensor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  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 95 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  29. 29.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 53. 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 35 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  35. 35.🔦 A light sensor reads 40 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 20 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  37. 37.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 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
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  40. 40.🔦 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 right sensor (b) the left sensor (c) both sensors (d) neither sensor

Answer key

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

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