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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 480 · 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 70 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  4. 4.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the wheel size (d) the black/white cut-off
  5. 5.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is loud (c) black is hot (d) black is wet
  6. 6.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  7. 7.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  8. 8.🔦 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
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 25. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  10. 10.⬛ 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
  11. 11.🔦 A light sensor reads 40 over black and 60 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 29. What is under the sensor? (a) the white floor (b) the black line
  13. 13.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  18. 18.🔦 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) both sensors (c) the left sensor (d) the right sensor
  19. 19.🔦 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 black line (b) the white floor
  20. 20.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  22. 22.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 35. 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 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  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 70. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  29. 29.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 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 black line (b) the white floor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  32. 32.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  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 10. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  35. 35.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) water (c) black (d) white
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  37. 37.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  39. 39.🔦 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) 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 15 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor

Answer key

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

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