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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 100 · 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 below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  5. 5.⬛ 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
  6. 6.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 18. What is under the sensor? (a) the white floor (b) the black line
  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 40. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  11. 11.🔦 A light sensor reads 30 over black and 60 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 48. What is under the sensor? (a) the white floor (b) the black line
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  14. 14.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  15. 15.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 A light sensor reads 10 over black and 80 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 36. What is under the sensor? (a) the black line (b) the white floor
  18. 18.🔦 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 black line (b) the white floor
  19. 19.🔦 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 right sensor (b) both sensors (c) the left sensor (d) neither sensor
  20. 20.⬛ A reading below the threshold means the sensor is over … (a) black (b) water (c) the sky (d) white
  21. 21.⬛ 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
  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 95. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  23. 23.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  25. 25.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  27. 27.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 36. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 23. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  30. 30.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) under the right sensor (d) far behind it
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  32. 32.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 47. What is under the sensor? (a) the black line (b) the white floor
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  35. 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 30. 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 75 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) neither 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 21. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
  40. 40.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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