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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 765 · 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 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 26. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 48. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ A reading below the threshold means the sensor is over … (a) white (b) black (c) water (d) the sky
  6. 6.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black soaks up light (d) black is wet
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 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
  9. 9.⬛ The threshold of a light sensor is … (a) the top speed (b) the black/white cut-off (c) the wheel size (d) the battery size
  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 white floor (b) the black line
  11. 11.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
  12. 12.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) far behind it (d) between the two sensors
  13. 13.🔦 A light sensor reads 30 over black and 70 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 40 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 31. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  23. 23.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 34. 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 30 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  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 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  28. 28.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  30. 30.🔦 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) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  32. 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 75. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 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
  34. 34.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 44. What is under the sensor? (a) the black line (b) the white floor
  37. 37.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. 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 75 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 53. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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