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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 809 · 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 60 over white. A good threshold is halfway between them. What is it?
  2. 2.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 68. What is under the sensor? (a) the black line (b) the white floor
  4. 4.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 43. What is under the sensor? (a) the white floor (b) the black line
  5. 5.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) water (d) the sky
  6. 6.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 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
  8. 8.🔦 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
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  10. 10.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  11. 11.🔦 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
  12. 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 19. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  17. 17.🔦 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) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  18. 18.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  19. 19.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) between the two sensors (d) under the right sensor
  20. 20.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 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
  22. 22.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the battery size (c) the top speed (d) the wheel size
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  24. 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 52. What is under the sensor? (a) the white floor (b) the black line
  25. 25.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  26. 26.⬛ 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
  27. 27.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 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) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 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
  30. 30.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 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) both sensors (c) neither sensor (d) the right sensor
  32. 32.🔦 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
  33. 33.🔦 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 white floor (b) the black line
  34. 34.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 58. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  36. 36.🔦 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
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 85. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left 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 40 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor

Answer key

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

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