Robotics Worksheet: Line Follower Light Sensors
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.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 45. What is under the sensor? (a) the white floor (b) the black line
- 2.🔦 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) both sensors (c) the left sensor (d) the right sensor
- 3.⬛ 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
- 4.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) between the two sensors (c) far behind it (d) under the right sensor
- 5.⬛ A reading below the threshold means the sensor is over … (a) water (b) white (c) black (d) the sky
- 6.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
- 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) the left sensor (d) neither sensor
- 8.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 23. What is under the sensor? (a) the white floor (b) the black line
- 9.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
- 10.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 19. What is under the sensor? (a) the black line (b) the white floor
- 11.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
- 12.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
- 13.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 56. What is under the sensor? (a) the white floor (b) the black line
- 14.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 69. What is under the sensor? (a) the black line (b) the white floor
- 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 43. What is under the sensor? (a) the black line (b) the white floor
- 16.🔦 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 right sensor (c) the left sensor (d) both sensors
- 17.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 29. What is under the sensor? (a) the white floor (b) the black line
- 18.🔦 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) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
- 19.⬛ The threshold of a light sensor is … (a) the wheel size (b) the top speed (c) the battery size (d) the black/white cut-off
- 20.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 17. What is under the sensor? (a) the white floor (b) the black line
- 21.🔦 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
- 22.🔦 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 black line (b) the white floor
- 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
- 24.🔦 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
- 25.🔦 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) both sensors (c) the left sensor (d) the right sensor
- 26.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 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
- 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 75. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
- 28.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 22. What is under the sensor? (a) the black line (b) the white floor
- 29.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 55. What is under the sensor? (a) the black line (b) the white floor
- 30.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
- 31.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 41. What is under the sensor? (a) the black line (b) the white floor
- 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
- 33.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
- 34.🔦 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
- 35.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 62. What is under the sensor? (a) the white floor (b) the black line
- 36.🔦 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 black line (b) the white floor
- 37.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
- 38.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
- 39.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 75. What is under the sensor? (a) the white floor (b) the black line
- 40.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 34. What is under the sensor? (a) the black line (b) the white floor
Answer key
- the white floor
- neither sensor
- black soaks up light
- between the two sensors
- black
- 35
- the right sensor
- the black line
- 50
- the black line
- 60
- the black line
- the white floor
- the white floor
- the black line
- the left sensor
- the black line
- the left sensor
- the black/white cut-off
- the black line
- the black line
- the black line
- the left sensor
- the white floor
- neither sensor
- the right sensor
- neither sensor
- the black line
- the white floor
- the white floor
- the black line
- neither sensor
- the white floor
- the black line
- the white floor
- the white floor
- 50
- 65
- the white floor
- the black line
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