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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 574 · 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 40 over black and 90 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 8. 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 70 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
  4. 4.⬛ The threshold of a light sensor is … (a) the wheel size (b) the black/white cut-off (c) the battery size (d) the top speed
  5. 5.🔦 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 black line (b) the white floor
  6. 6.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  8. 8.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 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
  11. 11.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  12. 12.⬛ A reading below the threshold means the sensor is over … (a) water (b) white (c) the sky (d) black
  13. 13.🔦 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
  14. 14.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black soaks up light (c) black is loud (d) black is wet
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  16. 16.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 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
  18. 18.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 11. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 58. What is under the sensor? (a) the white floor (b) the black line
  21. 21.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) far behind it (c) under the left sensor (d) between the two sensors
  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 light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 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 white floor (b) the black line
  25. 25.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 39. What is under the sensor? (a) the white floor (b) the black line
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  27. 27.🔦 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
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 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
  30. 30.🔦 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) 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 24. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 61. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 17. 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 30 over a black line and above 30 over the white floor. It reads 10. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. What is under the sensor? (a) the white floor (b) the black line
  38. 38.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 24. What is under the sensor? (a) the black line (b) the white floor
  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. 65
  2. the black line
  3. neither sensor
  4. the black/white cut-off
  5. the black line
  6. 55
  7. the black line
  8. 55
  9. 40
  10. the black line
  11. 50
  12. black
  13. the black line
  14. black soaks up light
  15. the right sensor
  16. 50
  17. neither sensor
  18. the black line
  19. 45
  20. the white floor
  21. between the two sensors
  22. 50
  23. 60
  24. the black line
  25. the black line
  26. the right sensor
  27. the white floor
  28. the white floor
  29. the white floor
  30. the left sensor
  31. the black line
  32. the white floor
  33. both sensors
  34. the black line
  35. 35
  36. the black line
  37. the white floor
  38. the white floor
  39. the black line
  40. 50

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