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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 760 · 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 90 over white. A good threshold is halfway between them. What is it?
  2. 2.⬛ The threshold of a light sensor is … (a) the wheel size (b) the battery size (c) the top speed (d) the black/white cut-off
  3. 3.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  5. 5.🔦 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
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 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
  7. 7.🔦 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
  8. 8.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 44. What is under the sensor? (a) the black line (b) the white floor
  9. 9.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 29. 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 27. What is under the sensor? (a) the white floor (b) the black line
  11. 11.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads 20 over black and 80 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 35. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  15. 15.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  18. 18.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is hot (c) black is wet (d) black soaks up light
  19. 19.🔦 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
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  23. 23.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 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) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  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) the right sensor (c) both sensors (d) neither sensor
  28. 28.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 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
  30. 30.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 22. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 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
  33. 33.⬛ 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
  34. 34.🔦 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
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 18. What is under the sensor? (a) the black line (b) the white floor
  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 15. 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 50 over a black line and above 50 over the white floor. It reads 31. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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