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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 110 · 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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  2. 2.🔦 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
  3. 3.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is hot (c) black soaks up light (d) black is loud
  4. 4.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 13. What is under the sensor? (a) the white floor (b) the black line
  5. 5.🔦 A light sensor reads 30 over black and 60 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 60 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 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  10. 10.⬛ A reading below the threshold means the sensor is over … (a) water (b) white (c) black (d) the sky
  11. 11.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 53. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  14. 14.🔦 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
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  17. 17.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 17. What is under the sensor? (a) the black line (b) the white floor
  19. 19.🔦 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
  20. 20.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 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
  22. 22.🔦 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 black line (b) the white floor
  23. 23.🔦 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 white floor (b) the black line
  24. 24.🔦 A light sensor reads 20 over black and 60 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 15 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  26. 26.🔦 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) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  27. 27.🔦 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
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 9. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  31. 31.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the wheel size (d) the black/white cut-off
  32. 32.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) far behind it (c) under the right sensor (d) under the left sensor
  33. 33.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 28. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 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
  36. 36.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  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 8. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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