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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 268 · 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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  2. 2.⬛ 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
  3. 3.⬛ A reading below the threshold means the sensor is over … (a) black (b) the sky (c) water (d) white
  4. 4.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  5. 5.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  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 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 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 black line (b) the white floor
  10. 10.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 17. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  13. 13.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  16. 16.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) between the two sensors (c) under the right sensor (d) under the left sensor
  18. 18.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.⬛ 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
  20. 20.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A light sensor reads 40 over black and 60 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 10 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  24. 24.🔦 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
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 73. 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 76. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  30. 30.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 65. 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 67. 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 70 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) neither 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 80 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  35. 35.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  37. 37.🔦 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 white floor (b) the black line
  38. 38.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 71. 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 40 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  40. 40.🔦 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 black line (b) the white floor

Answer key

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

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