Robotics Worksheet: Part 2 Test

Robotics lesson 20: Part 2 test: how robots move and sense · Set 235 · 40 questions

Robot tip (Find the topic, use the formula): Find the topic: moving, motors, gears, wheels, sensors, echo, line or gyro. Use the rule: teeth × turns; circumference × turns; 17 cm per ms of echo; below the threshold = black; right adds degrees. Check: put your answer back into the rule.

1. 1.🔦 A light sensor reads 30 over black and 90 over white. A good threshold is halfway between them. What is it?
2. 2.📡 An object is 34 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
3. 3.⚙️ A 12-tooth driver gear turns a 24-tooth driven gear. The driver turns 10 times. How many times does the driven gear turn?
4. 4.⚙️ 6 gears are in a row, each meshed with the next. Gear 1 turns clockwise. Which way does gear 6 turn? (a) anticlockwise (b) clockwise
5. 5.🔍 Which sensor helps a robot warn if motors get hot? (a) a camera (b) a distance sensor (c) a temperature sensor (d) a touch sensor
6. 6.🛞 A robot’s wheels have a diameter of 28 cm. Using π = 22/7, how many full turns must they make to roll 352 cm?
7. 7.🦾 A servo program runs:
   angle = 180
   angle = angle − 30
   angle = angle − 60
   angle = angle − 30
   angle = angle + 40
   To what angle (in degrees) does the servo turn in the end?
8. 8.⬛ The threshold of a light sensor is … (a) the black/white cut-off (b) the battery size (c) the wheel size (d) the top speed
9. 9.🔢 A gear ratio of 3 (driven ÷ driver) means the driven gear turns … (a) 3 times faster (b) 3 times bigger (c) 3 times slower (d) 3 times louder
10. 10.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 150°?
11. 11.📡 A robot stops if an object is closer than 50 cm. Its distance sensor hears the echo after 6 ms (sound: about 34 cm per ms). Does the robot stop? (a) No (b) Yes
12. 12.🛞 A motor’s 10-tooth gear drives a 20-tooth gear on the wheel axle. The wheels have a diameter of 35 cm (use π = 22/7). The motor turns 4 times. How far does the robot roll (in cm)?
13. 13.📡 An object is 119 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
14. 14.🛞 Which value of π is easiest for wheels of 7 cm, 14 cm or 21 cm? (a) 2/7 (b) 7/22 (c) 22/7 (d) 22
15. 15.Which job needs a light sensor? (a) hear a whistle (b) follow a black line (c) stay balanced upright (d) measure how far a box is
16. 16.📡 A distance sensor sends a sound pulse and hears the echo 5 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
17. 17.🔢 Gear ratio = driven teeth ÷ … (a) driver teeth (b) motor volts (c) number of gears (d) wheel size
18. 18.⬛ Why does a light sensor read a LOW number over a black line? (a) black is loud (b) black is wet (c) black soaks up light (d) black is hot
19. 19.⬛ A reading below the threshold means the sensor is over … (a) water (b) white (c) the sky (d) black
20. 20.⚙️ Which motor is best for turning a robot arm to exactly 45°? (a) a DC motor (b) a servo motor (c) a buzzer (d) a fan
21. 21.⬛ In a two-sensor line follower, both sensors see white. Where is the line? (a) under the left sensor (b) under the right sensor (c) between the two sensors (d) far behind it
22. 22.🛞 With the same motor speed, a bigger wheel makes the robot go … (a) backwards (b) slower (c) nowhere (d) faster
23. 23.📡 Which animal finds its way by echoes, like this sensor? (a) a bat (b) a goldfish (c) a cow (d) a snail
24. 24.⚙️ Which gear set-up gives this: “good for a racing toy”? (a) small drives big (b) big drives small
25. 25.🛞 Why do most indoor robots use wheels? (a) they climb stairs (b) fast and easy on floors (c) they look funny (d) they float
26. 26.Which job needs a touch sensor? (a) hear a whistle (b) know a button is pressed (c) stop before a wall (d) find the brightest spot
27. 27.🛞 A robot wheel has a diameter of 35 cm. Using π = 22/7, what is its circumference (in cm)?
28. 28.🛞 A robot’s wheels have a diameter of 35 cm. Using π = 22/7, how many full turns must they make to roll 770 cm?
29. 29.📡 A distance sensor sends a sound pulse and hears the echo 15 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
30. 30.📡 An object is 238 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
31. 31.📡 Why do we halve the echo’s total path? (a) the sensor is half (b) sound is slow (c) to make it smaller (d) it goes there and back
32. 32.📡 An object is 204 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
33. 33.🧭 A robot’s gyro reads 0° when it faces north and counts up to 359° as it turns right (east is 90°). It starts at 90°. It turns left 45°, then right 30°, then left 30°. What does the gyro read now (0° to 359°)?
34. 34.True or false: “has a signal wire” is true of a DC motor. (a) False (b) True
35. 35.🔍 Which sensor helps a robot read a QR code? (a) a touch sensor (b) a camera (c) a gyro sensor (d) a distance sensor
36. 36.🧭 A robot spins 30° every second. How many seconds does it take to turn 120°?
37. 37.🛞 Which way of moving suits this best: “a muddy building site”? (a) propellers (b) legs (c) wheels (d) tracks
38. 38.🔍 What does a gyro sensor measure? (a) sound (b) colour (c) temperature (d) turning (rotation)
39. 39.🛞 What is the main difficulty with legs for a robot? (a) they never tire (b) too fast on floors (c) they are too cheap (d) harder to balance
40. 40.🔦 A robot has a left and a right light sensor. Below 50 means black. The left sensor reads 70 and the right sensor reads 25. Which sensor is over the black line? (a) both sensors (b) the left sensor (c) neither sensor (d) the right sensor

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