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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 937 · 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 70 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 top speed (d) the wheel size
  3. 3.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 49. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  6. 6.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  7. 7.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is hot (c) black soaks up light (d) black is wet
  8. 8.🔦 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 white floor (b) the black line
  9. 9.🔦 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 white floor (b) the black line
  10. 10.⬛ 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) between the two sensors (d) far behind it
  11. 11.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 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
  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 below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  15. 15.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 20. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  18. 18.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 69. What is under the sensor? (a) the white floor (b) the black line
  21. 21.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 53. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  25. 25.🔦 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 left sensor (c) the right sensor (d) both sensors
  26. 26.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  27. 27.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) black (d) white
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 35. 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 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  32. 32.🔦 A light sensor reads 10 over black and 80 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 30 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
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  35. 35.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 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
  38. 38.🔦 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) neither sensor (c) the right sensor (d) both sensors
  39. 39.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 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 white floor (b) the black line

Answer key

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

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