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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 395 · 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 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  4. 4.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 85. What is under the sensor? (a) the black line (b) the white floor
  5. 5.⬛ 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
  6. 6.🔦 A light sensor reads 40 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 25 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  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 85. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  10. 10.🔦 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
  11. 11.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 15. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 37. What is under the sensor? (a) the white floor (b) the black line
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  14. 14.🔦 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
  15. 15.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  17. 17.⬛ A reading below the threshold means the sensor is over … (a) white (b) black (c) the sky (d) water
  18. 18.🔦 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
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 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
  20. 20.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 43. 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 40 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  23. 23.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  25. 25.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 5. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 64. What is under the sensor? (a) the black line (b) the white floor
  28. 28.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A light sensor reads 10 over black and 70 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 31. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 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 right sensor (b) both sensors (c) the left sensor (d) neither sensor
  33. 33.🔦 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
  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 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
  36. 36.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) between the two sensors (c) under the left sensor (d) far behind it
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  38. 38.⬛ 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
  39. 39.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 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

Answer key

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

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