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 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) neither sensor (b) both sensors (c) the left sensor (d) the right sensor
- 2.🔦 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 white floor (b) the black line
- 3.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
- 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 15. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
- 5.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
- 6.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 14. What is under the sensor? (a) the white floor (b) the black line
- 7.⬛ The threshold of a light sensor is … (a) the top speed (b) the wheel size (c) the battery size (d) the black/white cut-off
- 8.🔦 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) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
- 9.🔦 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 black line (b) the white floor
- 10.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 83. What is under the sensor? (a) the white floor (b) the black line
- 11.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) the left sensor (d) neither sensor
- 12.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
- 13.⬛ A reading below the threshold means the sensor is over … (a) the sky (b) white (c) water (d) black
- 14.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) far behind it (c) under the right sensor (d) between the two sensors
- 15.🔦 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 white floor (b) the black line
- 16.🔦 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
- 17.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 15 and the right sensor reads 70. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
- 18.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black is hot (d) black soaks up light
- 19.🔦 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 black line (b) the white floor
- 20.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 55. What is under the sensor? (a) the white floor (b) the black line
- 21.🔦 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
- 22.🔦 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) the left sensor (b) neither sensor (c) both sensors (d) the right sensor
- 23.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
- 24.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 85 and the right sensor reads 85. Which sensor is over the black line? (a) neither sensor (b) the left sensor (c) both sensors (d) the right sensor
- 25.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 44. What is under the sensor? (a) the white floor (b) the black line
- 26.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
- 27.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 40. What is under the sensor? (a) the black line (b) the white floor
- 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 10. What is under the sensor? (a) the white floor (b) the black line
- 29.🔦 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) neither sensor (d) both sensors
- 30.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
- 31.🔦 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) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
- 32.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 74. What is under the sensor? (a) the black line (b) the white floor
- 33.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 5. What is under the sensor? (a) the black line (b) the white floor
- 34.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
- 35.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 57. What is under the sensor? (a) the white floor (b) the black line
- 36.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 73. What is under the sensor? (a) the white floor (b) the black line
- 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 75. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
- 38.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 90 and the right sensor reads 15. Which sensor is over the black line? (a) both sensors (b) the right sensor (c) neither sensor (d) the left sensor
- 39.🔦 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 white floor (b) the black line
- 40.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 36. What is under the sensor? (a) the black line (b) the white floor
Answer key
- neither sensor
- the white floor
- 60
- the right sensor
- 50
- the black line
- the black/white cut-off
- both sensors
- the black line
- the white floor
- the left sensor
- 45
- black
- between the two sensors
- the black line
- the white floor
- the left sensor
- black soaks up light
- the white floor
- the black line
- the black line
- neither sensor
- 45
- neither sensor
- the black line
- 50
- the black line
- the black line
- the right sensor
- 50
- the left sensor
- the white floor
- the black line
- 35
- the black line
- the white floor
- the left sensor
- the right sensor
- the black line
- the white floor
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