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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 257 · 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.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) far behind it (c) between the two sensors (d) under the left sensor
  2. 2.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 53. What is under the sensor? (a) the black line (b) the white floor
  3. 3.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is hot (c) black soaks up light (d) black is loud
  5. 5.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 50. What is under the sensor? (a) the black line (b) the white floor
  6. 6.🔦 A light sensor reads 20 over black and 90 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 10 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
  8. 8.🔦 A light sensor reads 30 over black and 70 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 24. What is under the sensor? (a) the black line (b) the white floor
  10. 10.🔦 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
  11. 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 70. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  12. 12.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) water (c) white (d) black
  13. 13.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  14. 14.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 59. What is under the sensor? (a) the black line (b) the white floor
  15. 15.🔦 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
  16. 16.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  17. 17.🔦 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
  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 10. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  19. 19.🔦 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 white floor (b) the black line
  20. 20.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  21. 21.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  22. 22.⬛ The threshold of a light sensor is … (a) the wheel size (b) the battery size (c) the black/white cut-off (d) the top speed
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) the left 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 80 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 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 10 over black and 90 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
  28. 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 80. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 10. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  31. 31.🔦 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 white floor (b) the black line
  32. 32.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  33. 33.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 18. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 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) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 30. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  36. 36.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  37. 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 75. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  38. 38.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 79. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 11. What is under the sensor? (a) the white floor (b) the black line
  40. 40.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 30. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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