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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 209 · 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 60 over a black line and above 60 over the white floor. It reads 67. What is under the sensor? (a) the black line (b) the white floor
  2. 2.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) between the two sensors (d) under the right sensor
  5. 5.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is hot (d) black is wet
  6. 6.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 17. What is under the sensor? (a) the black line (b) the white floor
  8. 8.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) white (d) the sky
  9. 9.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  12. 12.🔦 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 white floor (b) the black line
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 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
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  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.⬛ The threshold of a light sensor is … (a) the wheel size (b) the black/white cut-off (c) the top speed (d) the battery size
  17. 17.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads 10 over black and 60 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 59. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 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 white floor (b) the black line
  21. 21.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
  23. 23.🔦 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
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 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
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 57. 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 64. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 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
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  30. 30.🔦 A light sensor reads 40 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 41. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
  33. 33.🔦 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 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 95 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  35. 35.🔦 A light sensor reads 30 over black and 90 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 90. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  38. 38.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 60. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor

Answer key

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

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