← Light sensors and lines lesson New set →

Robotics Worksheet: Line Follower Light Sensors

Robotics lesson 18: Light sensors and lines · Set 899 · 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 below 40 over a black line and above 40 over the white floor. It reads 24. What is under the sensor? (a) the black line (b) the white floor
  2. 2.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
  3. 3.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 85. What is under the sensor? (a) the white floor (b) the black line
  4. 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 60. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  5. 5.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black soaks up light (c) black is hot (d) black is loud
  6. 6.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 28. What is under the sensor? (a) the white floor (b) the black line
  7. 7.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 35. What is under the sensor? (a) the white floor (b) the black line
  8. 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  9. 9.⬛ A reading below the threshold means the sensor is over … (a) water (b) black (c) the sky (d) white
  10. 10.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 45. What is under the sensor? (a) the black line (b) the white floor
  11. 11.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
  12. 12.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
  13. 13.🔦 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) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
  14. 14.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
  15. 15.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) neither sensor (d) both sensors
  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 40 over black and 90 over white. A good threshold is halfway between them. What is it?
  18. 18.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) far behind it (b) under the left sensor (c) between the two sensors (d) under the right sensor
  19. 19.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 42. What is under the sensor? (a) the white floor (b) the black line
  20. 20.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
  21. 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 10 and the right sensor reads 40. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) both sensors (d) the left sensor
  22. 22.⬛ The threshold of a light sensor is … (a) the top speed (b) the black/white cut-off (c) the battery size (d) the wheel size
  23. 23.🔦 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
  24. 24.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 62. What is under the sensor? (a) the black line (b) the white floor
  25. 25.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
  26. 26.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 25. 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 36. What is under the sensor? (a) the white floor (b) the black line
  28. 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 54. What is under the sensor? (a) the black line (b) the white floor
  29. 29.🔦 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 black line (b) the white floor
  30. 30.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
  31. 31.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 15. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
  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 35. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
  33. 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 30. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
  34. 34.🔦 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) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
  35. 35.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 95 and the right sensor reads 90. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
  36. 36.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 20. What is under the sensor? (a) the white floor (b) the black line
  37. 37.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
  38. 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 and the right sensor reads 80. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
  39. 39.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
  40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) the right sensor (d) both sensors

Answer key

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

Free robotics lessons, practice and worksheets at talentjr.in/robotics-for-kids