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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 910 · 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 reading below the threshold means the sensor is over … (a) white (b) water (c) the sky (d) black
  2. 2.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 7. What is under the sensor? (a) the white floor (b) the black line
  4. 4.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is wet (d) black is hot
  5. 5.🔦 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
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 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
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 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
  9. 9.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 14. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
  14. 14.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 30. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  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.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the wheel size (d) the black/white cut-off
  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 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  22. 22.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 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) 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 90 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  27. 27.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
  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 20. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  30. 30.🔦 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
  31. 31.🔦 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) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  33. 33.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 33. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads 10 over black and 90 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 25 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
  36. 36.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 18. 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 85 and the right sensor reads 40. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  40. 40.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?

Answer key

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

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