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.⬛ Why does a light sensor read a LOW number over a black line? (a) black is wet (b) black is loud (c) black is hot (d) black soaks up light
- 2.⬛ A reading below the threshold means the sensor is over … (a) white (b) the sky (c) water (d) black
- 3.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 60 and the right sensor reads 60. Which sensor is over the black line? (a) both sensors (b) neither sensor (c) the right sensor (d) the left sensor
- 4.🔦 A light sensor reads 20 over black and 60 over white. A good threshold is halfway between them. What is it?
- 5.🔦 A light sensor reads 20 over black and 90 over white. A good threshold is halfway between them. What is it?
- 6.🔦 A light sensor reads 30 over black and 60 over white. A good threshold is halfway between them. What is it?
- 7.🔦 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
- 8.🔦 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
- 9.🔦 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 white floor (b) the black line
- 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) the right sensor (d) neither sensor
- 11.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 53. 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 85 and the right sensor reads 95. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) the right sensor (d) neither sensor
- 13.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 34. What is under the sensor? (a) the black line (b) the white floor
- 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 50 over a black line and above 50 over the white floor. It reads 64. What is under the sensor? (a) the white floor (b) the black line
- 16.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 31. What is under the sensor? (a) the white floor (b) the black line
- 17.🔦 A light sensor reads 20 over black and 80 over white. A good threshold is halfway between them. What is it?
- 18.🔦 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 white floor (b) the black line
- 19.🔦 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
- 20.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
- 21.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 40 and the right sensor reads 15. Which sensor is over the black line? (a) the right sensor (b) neither sensor (c) the left sensor (d) both sensors
- 22.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 80 and the right sensor reads 70. Which sensor is over the black line? (a) the left sensor (b) neither sensor (c) the right sensor (d) both sensors
- 23.🔦 A light sensor reads 10 over black and 70 over white. A good threshold is halfway between them. What is it?
- 24.🔦 A light sensor reads 40 over black and 60 over white. A good threshold is halfway between them. What is it?
- 25.🔦 A light sensor reads 20 over black and 70 over white. A good threshold is halfway between them. What is it?
- 26.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 60. What is under the sensor? (a) the black line (b) the white floor
- 27.🔦 A light sensor reads 10 over black and 60 over white. A good threshold is halfway between them. What is it?
- 28.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 15. 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 33. What is under the sensor? (a) the white floor (b) the black line
- 30.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 12. What is under the sensor? (a) the black line (b) the white floor
- 31.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 52. What is under the sensor? (a) the white floor (b) the black line
- 32.🔦 A light sensor reads below 40 over a black line and above 40 over the white floor. It reads 51. What is under the sensor? (a) the white floor (b) the black line
- 33.🔦 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
- 34.🔦 A light sensor reads below 30 over a black line and above 30 over the white floor. It reads 47. What is under the sensor? (a) the white floor (b) the black line
- 35.🔦 A light sensor reads 10 over black and 80 over white. A good threshold is halfway between them. What is it?
- 36.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 65. Which sensor is over the black line? (a) the left sensor (b) the right sensor (c) neither sensor (d) both sensors
- 37.🔦 A light sensor reads 40 over black and 70 over white. A good threshold is halfway between them. What is it?
- 38.🔦 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
- 39.🔦 A light sensor reads 40 over black and 80 over white. A good threshold is halfway between them. What is it?
- 40.🔦 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 white floor (b) the black line
Answer key
- black soaks up light
- black
- neither sensor
- 40
- 55
- 45
- the white floor
- the white floor
- the black line
- both sensors
- the white floor
- neither sensor
- the white floor
- between the two sensors
- the white floor
- the black line
- 50
- the black line
- the black line
- 60
- both sensors
- neither sensor
- 40
- 50
- 45
- the white floor
- 35
- the black line
- the white floor
- the black line
- the white floor
- the white floor
- the black line
- the white floor
- 45
- neither sensor
- 55
- the white floor
- 60
- the white floor
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