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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 657 · 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 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 20 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 22. What is under the sensor? (a) the black line (b) the white floor
  4. 4.⬛ The threshold of a light sensor is … (a) the top speed (b) the wheel size (c) the battery size (d) the black/white cut-off
  5. 5.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
  6. 6.⬛ 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 left sensor (d) under the right sensor
  7. 7.🔦 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 white floor (b) the black line
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  9. 9.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) water (d) black
  10. 10.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black soaks up light (d) black is wet
  11. 11.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  13. 13.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 69. 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 20 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  16. 16.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 19. What is under the sensor? (a) the black line (b) the white floor
  17. 17.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  19. 19.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  22. 22.🔦 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 white floor (b) the black line
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  25. 25.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  26. 26.🔦 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
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 20. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  28. 28.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
  30. 30.🔦 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 white floor (b) the black line
  31. 31.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 A light sensor reads 30 over black and 70 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 20 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  34. 34.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
  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 65. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
  36. 36.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 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
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 10. Which sensor is over the black line? (a) both sensors (b) the right sensor (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 85 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 40. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor

Answer key

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

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