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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 819 · 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 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 36. What is under the sensor? (a) the white floor (b) the black line
  4. 4.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black soaks up light (c) black is hot (d) black is loud
  5. 5.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  7. 7.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
  9. 9.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  10. 10.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor
  11. 11.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) between the two sensors (c) under the right sensor (d) under the left sensor
  12. 12.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 31. 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 30 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  14. 14.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 57. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 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 black line (b) the white floor
  18. 18.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  24. 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 45. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  26. 26.⬛ The threshold of a light sensor is … (a) the top speed (b) the battery size (c) the black/white cut-off (d) the wheel size
  27. 27.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 58. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads 40 over black and 90 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 35. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  32. 32.⬛ A reading below the threshold means the sensor is over … (a) black (b) the sky (c) white (d) water
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 72. 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 45. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 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
  37. 37.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 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
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) the left sensor (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 70 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor

Answer key

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

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