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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 15 · 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 below 40 over a black line and above 40 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  2. 2.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) black (c) white (d) water
  3. 3.⬛ 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
  4. 4.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the top speed (c) the wheel size (d) the battery size
  6. 6.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) under the left sensor (d) between the two sensors
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  8. 8.🔦 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 black line (b) the white floor
  9. 9.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 48. What is under the sensor? (a) the white floor (b) the black line
  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 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 white floor (b) the black line
  12. 12.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 17. 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 20 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  14. 14.🔦 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) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  16. 16.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 35. What is under the sensor? (a) the white floor (b) the black line
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  18. 18.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 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 black line (b) the white floor
  20. 20.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  26. 26.🔦 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 right sensor (c) neither sensor (d) the left 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 51. 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 85 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  30. 30.🔦 A light sensor reads 40 over black and 60 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 65 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
  32. 32.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  34. 34.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 60. What is under the sensor? (a) the black line (b) the white floor
  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 20. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  38. 38.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 62. 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 25 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor

Answer key

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

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