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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 602 · 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.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the battery size (c) the wheel size (d) the top speed
  3. 3.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 82. What is under the sensor? (a) the black line (b) the white floor
  5. 5.🔦 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
  6. 6.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black is hot (d) black soaks up light
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 71. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  11. 11.⬛ A reading below the threshold means the sensor is over … (a) white (b) water (c) the sky (d) black
  12. 12.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 52. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  16. 16.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) under the right sensor (d) between the two sensors
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 35. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  20. 20.🔦 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
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  22. 22.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  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 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 black line (b) the white floor
  27. 27.🔦 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
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 10. 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 20 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  31. 31.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  34. 34.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 49. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  38. 38.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  40. 40.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 8. What is under the sensor? (a) the black line (b) the white floor

Answer key

  1. 60
  2. the black/white cut-off
  3. 50
  4. the white floor
  5. the black line
  6. black soaks up light
  7. the white floor
  8. 50
  9. the right sensor
  10. the right sensor
  11. black
  12. the white floor
  13. the white floor
  14. 45
  15. both sensors
  16. between the two sensors
  17. the left sensor
  18. the black line
  19. the right sensor
  20. the black line
  21. both sensors
  22. 50
  23. the black line
  24. both sensors
  25. 40
  26. the white floor
  27. the white floor
  28. both sensors
  29. both sensors
  30. the right sensor
  31. 60
  32. both sensors
  33. both sensors
  34. 35
  35. the black line
  36. the right sensor
  37. both sensors
  38. 55
  39. both sensors
  40. the black line

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