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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 656 · 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 70 over white. A good threshold is halfway between them. What is it?
  2. 2.⬛ 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
  3. 3.🔦 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 black line (b) the white floor
  4. 4.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 10. What is under the sensor? (a) the white floor (b) the black line
  5. 5.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 49. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 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
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  10. 10.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 49. What is under the sensor? (a) the white floor (b) the black line
  11. 11.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  13. 13.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) water (d) the sky
  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 60 over a black line and above 60 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  16. 16.⬛ 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
  17. 17.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 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
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 80. 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 90 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
  22. 22.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 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) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  24. 24.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 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
  26. 26.🔦 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 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 80 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
  28. 28.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  30. 30.⬛ 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
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 90. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  32. 32.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 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
  34. 34.🔦 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) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  35. 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 74. What is under the sensor? (a) the white floor (b) the black line
  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 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  37. 37.🔦 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 black line (b) the white floor
  38. 38.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor

Answer key

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

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