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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 85 · 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.⬛ The threshold of a light sensor is … (a) the wheel size (b) the top speed (c) the battery size (d) the black/white cut-off
  2. 2.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  5. 5.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  7. 7.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) water (d) the sky
  8. 8.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is wet (c) black is loud (d) black soaks up light
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 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
  10. 10.🔦 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 white floor (b) the black line
  11. 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 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
  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 light sensor reads 40 over black and 70 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 15 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  16. 16.🔦 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 white floor (b) the black line
  17. 17.⬛ 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
  18. 18.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 77. What is under the sensor? (a) the white floor (b) the black line
  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 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 63. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  23. 23.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  24. 24.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 40. 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 35 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  26. 26.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 37. 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 26. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 70. What is under the sensor? (a) the white floor (b) the black line
  30. 30.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 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
  32. 32.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 37. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 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
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 95. 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 20 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 15 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  38. 38.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 69. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 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) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  40. 40.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?

Answer key

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

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