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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 797 · 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 90 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 30 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 7. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  5. 5.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is hot (d) black is wet
  6. 6.⬛ A reading below the threshold means the sensor is over … (a) water (b) the sky (c) white (d) black
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  11. 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 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
  13. 13.⬛ The threshold of a light sensor is … (a) the top speed (b) the wheel size (c) the black/white cut-off (d) the battery size
  14. 14.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 95. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  18. 18.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 27. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 50. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 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 white floor (b) the black line
  21. 21.🔦 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
  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 25. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  25. 25.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 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
  29. 29.🔦 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 black line (b) the white floor
  30. 30.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  31. 31.🔦 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) neither sensor (c) the left sensor (d) the right sensor
  32. 32.🔦 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) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  33. 33.🔦 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
  34. 34.🔦 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
  35. 35.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 20. What is under the sensor? (a) the black line (b) the white floor
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 25. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  37. 37.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) under the right sensor (d) between the two sensors
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  40. 40.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?

Answer key

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

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