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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 606 · 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 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  4. 4.⬛ A reading below the threshold means the sensor is over … (a) white (b) water (c) black (d) the sky
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  6. 6.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 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
  8. 8.🔦 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) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  9. 9.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) under the right sensor (d) between the two sensors
  10. 10.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  11. 11.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is hot (c) black is loud (d) black soaks up light
  12. 12.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 16. What is under the sensor? (a) the black line (b) the white floor
  14. 14.🔦 A light sensor reads 40 over black and 60 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 90 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  16. 16.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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 white floor (b) the black line
  18. 18.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 11. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 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
  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 90. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 33. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  24. 24.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the black/white cut-off (d) the wheel size
  25. 25.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 75. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads 20 over black and 60 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 63. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 26. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 60. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  34. 34.🔦 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
  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 90. 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 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  39. 39.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 74. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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