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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 301 · 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 60 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  3. 3.⬛ 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
  4. 4.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 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
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  10. 10.🔦 A light sensor reads 40 over black and 80 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 15 and the right sensor reads 65. 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 60 over a black line and above 60 over the white floor. It reads 56. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 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
  14. 14.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is wet (c) black is loud (d) black soaks up light
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  16. 16.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
  17. 17.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 61. 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 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  19. 19.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) under the left sensor (c) under the right sensor (d) far behind it
  20. 20.🔦 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 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 20 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  22. 22.🔦 A light sensor reads 40 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 39. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 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
  26. 26.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 83. 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 80 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  29. 29.🔦 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 black line (b) the white floor
  30. 30.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  32. 32.🔦 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 white floor (b) the black line
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 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
  36. 36.🔦 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 black line (b) the white floor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  38. 38.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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