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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 669 · 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 light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  4. 4.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 79. What is under the sensor? (a) the black line (b) the white floor
  5. 5.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
  6. 6.🔦 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 black line (b) the white floor
  7. 7.🔦 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
  8. 8.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 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
  10. 10.⬛ 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 loud (d) black is hot
  11. 11.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) black (d) water
  12. 12.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  14. 14.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 12. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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 black line (b) the white floor
  18. 18.⬛ 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
  19. 19.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 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
  22. 22.🔦 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) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  23. 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 80. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 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
  25. 25.⬛ The threshold of a light sensor is … (a) the wheel size (b) the battery size (c) the top speed (d) the black/white cut-off
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  27. 27.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 6. 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 43. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 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 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 10 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  31. 31.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 57. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 75. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  34. 34.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A light sensor reads 20 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 33. 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 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
  38. 38.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 33. What is under the sensor? (a) the black line (b) the white floor
  39. 39.🔦 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 black line (b) the white floor
  40. 40.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 59. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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