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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 515 · 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 is wet (b) black is hot (c) black soaks up light (d) black is loud
  2. 2.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  4. 4.🔦 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) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  5. 5.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) under the right sensor (c) far behind it (d) between the two sensors
  6. 6.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  7. 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 10. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
  8. 8.🔦 A light sensor reads 10 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 10. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors
  10. 10.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 44. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 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
  12. 12.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 15. 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 35 and the right sensor reads 35. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
  15. 15.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 84. What is under the sensor? (a) the black line (b) the white floor
  16. 16.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 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
  17. 17.🔦 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
  18. 18.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
  19. 19.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 81. What is under the sensor? (a) the black line (b) the white floor
  20. 20.⬛ A reading below the threshold means the sensor is over … (a) black (b) white (c) water (d) the sky
  21. 21.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  22. 22.🔦 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
  23. 23.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  24. 24.🔦 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 black line (b) the white floor
  25. 25.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 25. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
  27. 27.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  28. 28.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
  29. 29.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  30. 30.🔦 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 left sensor (d) the right sensor
  31. 31.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 65. What is under the sensor? (a) the white floor (b) the black line
  33. 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 38. What is under the sensor? (a) the white floor (b) the black line
  34. 34.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 39. What is under the sensor? (a) the black line (b) the white floor
  35. 35.⬛ The threshold of a light sensor is … (a) the battery size (b) the top speed (c) the wheel size (d) the black/white cut-off
  36. 36.🔦 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) both sensors (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 42. What is under the sensor? (a) the white floor (b) the black line
  39. 39.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 27. What is under the sensor? (a) the black line (b) the white floor

Answer key

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

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