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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 128 · 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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  2. 2.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 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
  5. 5.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) white (d) water
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 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
  7. 7.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the black/white cut-off (d) the top speed
  8. 8.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A light sensor reads 30 over black and 80 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 80 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  12. 12.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 54. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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
  18. 18.⬛ 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
  19. 19.🔦 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 white floor (b) the black line
  20. 20.🔦 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 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 60 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  22. 22.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  23. 23.🔦 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) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  25. 25.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  26. 26.🔦 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 black line (b) the white floor
  27. 27.🔦 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) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  28. 28.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 15. What is under the sensor? (a) the white floor (b) the black line
  31. 31.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) under the right sensor (d) far behind it
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  33. 33.🔦 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
  34. 34.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 36. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 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 white floor (b) the black line
  36. 36.🔦 A light sensor reads 40 over black and 60 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 70 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  38. 38.🔦 A light sensor reads 30 over black and 60 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 15 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  40. 40.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 26. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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