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 42. What is under the sensor? (a) the black line (b) the white floor
- 2.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 51. What is under the sensor? (a) the black line (b) the white floor
- 3.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the right sensor (b) far behind it (c) between the two sensors (d) under the left sensor
- 4.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 30 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
- 5.🔦 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
- 6.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
- 7.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 78. What is under the sensor? (a) the white floor (b) the black line
- 8.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 85. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) both sensors (d) neither sensor
- 9.🔦 A light sensor reads 30 over black and 70 over white. A good threshold is halfway between them. What is it?
- 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 25. Which sensor is over the black line? (a) the left sensor (b) both sensors (c) neither sensor (d) the right sensor
- 11.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 65. What is under the sensor? (a) the black line (b) the white floor
- 12.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 20. Which sensor is over the black line? (a) the right sensor (b) both sensors (c) neither sensor (d) the left sensor
- 13.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
- 14.🔦 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) the left sensor (b) both sensors (c) the right sensor (d) neither sensor
- 15.🔦 A light sensor reads below 50 over a black line and above 50 over the white floor. It reads 38. What is under the sensor? (a) the black line (b) the white floor
- 16.🔦 A light sensor reads 10 over black and 90 over white. A good threshold is halfway between them. What is it?
- 17.🔦 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
- 18.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 52. What is under the sensor? (a) the black line (b) the white floor
- 19.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 37. What is under the sensor? (a) the black line (b) the white floor
- 20.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 25 and the right sensor reads 20. Which sensor is over the black line? (a) neither sensor (b) both sensors (c) the right sensor (d) the left sensor
- 21.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 25. What is under the sensor? (a) the white floor (b) the black line
- 22.⬛ Why does a light sensor read a LOW number over a black line? (a) black is hot (b) black is wet (c) black is loud (d) black soaks up light
- 23.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 65 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
- 24.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 40. What is under the sensor? (a) the white floor (b) the black line
- 25.⬛ 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
- 26.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 21. What is under the sensor? (a) the white floor (b) the black line
- 27.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
- 28.🔦 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
- 29.🔦 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
- 30.🔦 A light sensor reads 30 over black and 60 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 10 and the right sensor reads 30. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
- 32.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 75 and the right sensor reads 10. Which sensor is over the black line? (a) the right sensor (b) the left sensor (c) both sensors (d) neither sensor
- 33.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 20. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the left sensor (d) the right sensor
- 34.🔦 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
- 35.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
- 36.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
- 37.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 35. Which sensor is over the black line? (a) neither sensor (b) the right sensor (c) both sensors (d) the left sensor
- 38.🔦 A light sensor reads 30 over black and 80 over white. A good threshold is halfway between them. What is it?
- 39.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 32. What is under the sensor? (a) the black line (b) the white floor
- 40.🔦 A light sensor reads below 60 over a black line and above 60 over the white floor. It reads 46. What is under the sensor? (a) the white floor (b) the black line
Answer key
- the white floor
- the black line
- between the two sensors
- both sensors
- the white floor
- 55
- the white floor
- neither sensor
- 50
- both sensors
- the white floor
- the right sensor
- 45
- the right sensor
- the black line
- 50
- the black line
- the white floor
- the black line
- both sensors
- the black line
- black soaks up light
- neither sensor
- the black line
- the black/white cut-off
- the black line
- 40
- the white floor
- the white floor
- 45
- both sensors
- the right sensor
- the right sensor
- the white floor
- 50
- 40
- both sensors
- 55
- the black line
- the black line
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