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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 955 · 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 30. What is under the sensor? (a) the black line (b) the white floor
  2. 2.⬛ 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
  3. 3.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 78. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
  6. 6.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 39. What is under the sensor? (a) the black line (b) the white floor
  7. 7.⬛ 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
  8. 8.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 32. What is under the sensor? (a) the black line (b) the white floor
  9. 9.🔦 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 white floor (b) the black line
  10. 10.🔦 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 left sensor (b) neither sensor (c) the right sensor (d) both sensors
  11. 11.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 22. What is under the sensor? (a) the black line (b) the white floor
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 65. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  13. 13.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  14. 14.⬛ 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
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads 20 over black and 70 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 37. What is under the sensor? (a) the white floor (b) the black line
  18. 18.🔦 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) neither sensor (c) both sensors (d) the right sensor
  19. 19.🔦 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
  20. 20.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  22. 22.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  23. 23.🔦 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 black line (b) the white floor
  24. 24.🔦 A light sensor reads 30 over black and 70 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 70 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  27. 27.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 16. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 20. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  31. 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 75. What is under the sensor? (a) the black line (b) the white floor
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 76. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  35. 35.🔦 A light sensor reads 10 over black and 90 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 35. 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 35 and the right sensor reads 15. 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 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 53. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?

Answer key

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

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