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 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
- 2.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
- 3.🔦 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) both sensors (c) neither sensor (d) the left sensor
- 4.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
- 5.🔦 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 black line (b) the white floor
- 6.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 60. What is under the sensor? (a) the white floor (b) the black line
- 7.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 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
- 8.⬛ A reading below the threshold means the sensor is over … (a) black (b) the sky (c) white (d) water
- 9.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
- 10.⬛ The threshold of a light sensor is … (a) the wheel size (b) the battery size (c) the top speed (d) the black/white cut-off
- 11.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
- 12.🔦 A light sensor reads 40 over black and 90 over white. A good threshold is halfway between them. What is it?
- 13.🔦 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
- 14.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
- 15.🔦 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) neither sensor (b) the right sensor (c) the left sensor (d) both sensors
- 16.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black soaks up light (c) black is hot (d) black is wet
- 17.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
- 18.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
- 19.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 20 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
- 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 35 and the right sensor reads 85. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
- 21.🔦 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
- 22.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 58. What is under the sensor? (a) the white floor (b) the black line
- 23.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 72. What is under the sensor? (a) the black line (b) the white floor
- 24.🔦 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 black line (b) the white floor
- 25.🔦 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 black line (b) the white floor
- 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 13. What is under the sensor? (a) the black line (b) the white floor
- 27.🔦 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 white floor (b) the black line
- 28.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 71. What is under the sensor? (a) the black line (b) the white floor
- 29.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
- 30.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 65. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor
- 31.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
- 32.🔦 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
- 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 65. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
- 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 75. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
- 35.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) between the two sensors (b) far behind it (c) under the right sensor (d) under the left sensor
- 36.🔦 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 black line (b) the white floor
- 37.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 56. What is under the sensor? (a) the white floor (b) the black line
- 38.🔦 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) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
- 39.🔦 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 black line (b) the white floor
- 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 90. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
Answer key
- the black line
- 40
- the right sensor
- 50
- the black line
- the white floor
- the right sensor
- black
- 45
- the black/white cut-off
- 50
- 65
- the white floor
- 60
- both sensors
- black soaks up light
- 55
- the white floor
- both sensors
- the left sensor
- the white floor
- the white floor
- the white floor
- the white floor
- the black line
- the black line
- the white floor
- the white floor
- 35
- the left sensor
- 40
- the white floor
- the left sensor
- the left sensor
- between the two sensors
- the white floor
- the black line
- neither sensor
- the black line
- neither sensor
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