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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 520 · 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 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  2. 2.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black is hot (d) black soaks up light
  3. 3.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) under the right sensor (d) between the two sensors
  4. 4.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  5. 5.🔦 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 black line (b) the white floor
  6. 6.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  7. 7.⬛ A reading below the threshold means the sensor is over … (a) white (b) black (c) water (d) the sky
  8. 8.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  10. 10.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 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
  11. 11.🔦 A light sensor reads 20 over black and 60 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 30 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  13. 13.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 8. What is under the sensor? (a) the white floor (b) the black line
  14. 14.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 70. What is under the sensor? (a) the white floor (b) the black line
  16. 16.🔦 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) 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 85 and the right sensor reads 70. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  18. 18.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  19. 19.⬛ The threshold of a light sensor is … (a) the battery size (b) the wheel size (c) the black/white cut-off (d) the top speed
  20. 20.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 44. What is under the sensor? (a) the black line (b) the white floor
  21. 21.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 73. What is under the sensor? (a) the white floor (b) the black line
  22. 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  23. 23.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 33. 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 60 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
  25. 25.🔦 A light sensor reads 10 over black and 90 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 95 and the right sensor reads 80. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  27. 27.🔦 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
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 48. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 25. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  30. 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 75. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
  31. 31.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 26. What is under the sensor? (a) the white floor (b) the black line
  32. 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  33. 33.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor
  34. 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 35. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 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
  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 robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
  38. 38.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  39. 39.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 35. What is under the sensor? (a) the black line (b) the white floor
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor

Answer key

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

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