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Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 45 · 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 reading below the threshold means the sensor is over … (a) white (b) the sky (c) black (d) water
  2. 2.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 40. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  3. 3.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  4. 4.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the wheel size (c) the battery size (d) the top speed
  5. 5.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 80. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  6. 6.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  7. 7.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
  8. 8.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
  9. 9.🔦 A light sensor reads 30 over black and 80 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 25 and the right sensor reads 60. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  11. 11.🔦 A light sensor reads 20 over black and 70 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 15 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
  13. 13.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is loud (c) black is wet (d) black soaks up light
  14. 14.🔦 A light sensor reads 10 over black and 90 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 66. 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 60 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  17. 17.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  18. 18.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 24. 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 84. 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 65 and the right sensor reads 25. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  21. 21.🔦 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
  22. 22.🔦 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) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
  23. 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 95. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
  24. 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  25. 25.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 67. What is under the sensor? (a) the black line (b) the white floor
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
  27. 27.🔦 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
  28. 28.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 35. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  29. 29.🔦 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) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
  30. 30.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 75. What is under the sensor? (a) the black line (b) the white floor
  31. 31.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
  32. 32.🔦 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
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  34. 34.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 39. What is under the sensor? (a) the black line (b) the white floor
  35. 35.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 82. What is under the sensor? (a) the white floor (b) the black line
  36. 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 10. 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 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  38. 38.⬛ 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
  39. 39.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 35. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
  40. 40.🔦 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

Answer key

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

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