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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 7 · 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 battery size (c) the black/white cut-off (d) the top speed
  2. 2.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) water (d) black
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  4. 4.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 53. What is under the sensor? (a) the white floor (b) the black line
  6. 6.🔦 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 black line (b) the white floor
  7. 7.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 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 black line (b) the white floor
  10. 10.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  12. 12.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the right sensor (c) between the two sensors (d) under the left sensor
  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 30 over black and 80 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 85. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  16. 16.🔦 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
  17. 17.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 49. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  19. 19.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  21. 21.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black is hot (d) black soaks up light
  22. 22.🔦 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 black line (b) the white floor
  23. 23.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 52. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 66. 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 80 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  26. 26.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 61. What is under the sensor? (a) the white floor (b) the black line
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  31. 31.🔦 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
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 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
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 95. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  39. 39.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?

Answer key

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

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