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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 277 · 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 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  3. 3.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) black (d) water
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 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
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 34. What is under the sensor? (a) the white floor (b) the black line
  8. 8.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 67. What is under the sensor? (a) the white floor (b) the black line
  9. 9.🔦 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
  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 15. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  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 light sensor reads below 40 over a black line and above 40 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  16. 16.⬛ The threshold of a light sensor is … (a) the wheel size (b) the top speed (c) the black/white cut-off (d) the battery size
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  18. 18.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black soaks up light (d) black is hot
  19. 19.🔦 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
  20. 20.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) under the left sensor (c) far behind it (d) between the two sensors
  21. 21.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  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 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  25. 25.🔦 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 black line (b) the white floor
  26. 26.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 65. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 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 white floor (b) the black line
  28. 28.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 69. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads 30 over black and 80 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 90 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  31. 31.🔦 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 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 54. What is under the sensor? (a) the black line (b) the white floor
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  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 40. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  35. 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 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
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 60. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 65. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  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. 50
  2. the right sensor
  3. 45
  4. black
  5. neither sensor
  6. neither sensor
  7. the black line
  8. the white floor
  9. the white floor
  10. both sensors
  11. 50
  12. the white floor
  13. the white floor
  14. 40
  15. 65
  16. the black/white cut-off
  17. neither sensor
  18. black soaks up light
  19. the black line
  20. between the two sensors
  21. the black line
  22. the right sensor
  23. the white floor
  24. 55
  25. the black line
  26. the white floor
  27. the white floor
  28. the white floor
  29. 55
  30. the right sensor
  31. the black line
  32. the white floor
  33. the right sensor
  34. the right sensor
  35. the black line
  36. 45
  37. the black line
  38. the left sensor
  39. neither sensor
  40. 60

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