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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 851 · 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.⬛ Why does a light sensor read a LOW number over a black line? (a) black soaks up light (b) black is wet (c) black is loud (d) black is hot
  2. 2.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 63. What is under the sensor? (a) the white floor (b) the black line
  3. 3.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 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
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left 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 light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  11. 11.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the battery size (c) the wheel size (d) the top speed
  12. 12.⬛ 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
  13. 13.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  14. 14.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 66. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 10. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 A light sensor reads 20 over black and 80 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 80. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  18. 18.🔦 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) the right sensor (c) the left sensor (d) both sensors
  19. 19.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  20. 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 30. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  22. 22.⬛ A reading below the threshold means the sensor is over … (a) white (b) water (c) black (d) the sky
  23. 23.🔦 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 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 40 and the right sensor reads 90. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  25. 25.🔦 A light sensor reads 30 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 72. What is under the sensor? (a) the white floor (b) the black line
  27. 27.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  29. 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 6. What is under the sensor? (a) the black line (b) the white floor
  30. 30.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 52. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 22. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 39. What is under the sensor? (a) the white floor (b) the black line
  35. 35.🔦 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 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 10 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  37. 37.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 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
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 41. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 70. What is under the sensor? (a) the white floor (b) the black line

Answer key

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

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