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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 240 · 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.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the top speed (c) the wheel size (d) the battery size
  2. 2.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  4. 4.🔦 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 right sensor (b) neither sensor (c) the left sensor (d) both sensors
  5. 5.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 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
  7. 7.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 81. What is under the sensor? (a) the white floor (b) the black line
  9. 9.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A light sensor reads 40 over black and 90 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 60 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  13. 13.🔦 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
  14. 14.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 24. What is under the sensor? (a) the white floor (b) the black line
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  16. 16.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) between the two sensors (d) under the right sensor
  17. 17.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 75. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
  20. 20.🔦 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) both sensors (c) the right sensor (d) the left sensor
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 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
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 95. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  25. 25.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  26. 26.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black soaks up light (d) black is hot
  27. 27.🔦 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 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 75. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  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 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 white floor (b) the black line
  32. 32.🔦 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) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  33. 33.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  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 85. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  35. 35.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  37. 37.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  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 80. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  40. 40.🔦 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 black line (b) the white floor

Answer key

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

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