Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 41 · 40 questions

Remember (Measure it, then move it): Match the sensor to the quantity: light, heat, distance, movement, soil wetness, sound, gas or rain. Match the actuator to the action: spin (motor), exact angle (servo), beep (buzzer), light (LED), water (pump), numbers (display). Echo distance = 17 × echo time in ms (cm), because the sound goes there and back.

1. 1.🔍 An object is 68 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
2. 2.Which job needs a distance sensor? (a) switch on lamps at dusk (b) stop a robot near walls (c) switch on with a clap (d) measure classroom noise
3. 3.⚙️ What is an actuator? (a) a program (b) an output that acts (c) a sensor (d) a battery
4. 4.Which job needs a rain sensor? (a) stop a robot near walls (b) start a fan when hot (c) close a window in rain (d) switch on with a clap
5. 5.True or false: to close a window in rain, use a motion sensor. (a) True (b) False
6. 6.⚙️ Which actuator would you use to turn to an exact angle? (a) an LED (b) a motor (c) a servo motor (d) a display
7. 7.🔍 A distance sensor sends a sound pulse and hears the echo 14 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
8. 8.🔍 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?
9. 9.Which job needs a sound sensor? (a) start a fan when hot (b) spot someone walking in (c) measure classroom noise (d) warn of a gas leak
10. 10.Which job needs a pump? (a) show a status light (b) turn to an exact angle (c) beep an alarm (d) move water to plants
11. 11.Which job needs a buzzer? (a) open a gate to 90° (b) show the temperature (c) beep an alarm (d) move water to plants
12. 12.Which job needs an LED? (a) show a status light (b) spin a robot’s wheels (c) beep an alarm (d) show the temperature
13. 13.True or false: to make a parking alarm, use a sound sensor. (a) True (b) False
14. 14.⚙️ Which actuator would you use to beep an alarm? (a) a motor (b) a servo motor (c) an LED (d) a buzzer
15. 15.True or false: to close a window in rain, use a rain sensor. (a) False (b) True
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.Which job needs a soil moisture sensor? (a) water a dry plant (b) open blinds at sunrise (c) make a parking alarm (d) stop a robot near walls
18. 18.Which job needs a servo motor? (a) open a gate to 90° (b) move water to plants (c) show the temperature (d) spin a robot’s wheels
19. 19.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) a fuse (c) a power source (d) an input
20. 20.Which job needs a gas sensor? (a) warn of a gas leak (b) switch on lamps at dusk (c) keep an incubator warm (d) start a fan when hot
21. 21.True or false: to stop a robot near walls, use a light sensor. (a) False (b) True
22. 22.🔍 Which sensor would you use to stop a robot near walls? (a) a temperature sensor (b) a sound sensor (c) a rain sensor (d) a distance sensor
23. 23.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a display (b) a servo motor (c) a motor (d) an LED
24. 24.🔍 Which sensor would you use to keep an incubator warm? (a) a distance sensor (b) a motion sensor (c) a temperature sensor (d) a light sensor
25. 25.🔍 An object is 323 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
26. 26.⚙️ Which actuator would you use to move water to plants? (a) a pump (b) a motor (c) a buzzer (d) a display
27. 27.🔍 Which sensor would you use to switch on with a clap? (a) a sound sensor (b) a gas sensor (c) a soil moisture sensor (d) a temperature sensor
28. 28.Which job needs a temperature sensor? (a) warn of a gas leak (b) keep an incubator warm (c) switch on lamps at dusk (d) stop a robot near walls
29. 29.True or false: to switch on lamps at dusk, use a light sensor. (a) False (b) True
30. 30.🔍 Which sensor would you use to switch on lamps at dusk? (a) a gas sensor (b) a light sensor (c) a temperature sensor (d) a sound sensor
31. 31.🔍 Which sensor would you use to make a parking alarm? (a) a sound sensor (b) a distance sensor (c) a gas sensor (d) a motion sensor
32. 32.🔍 Which sensor would you use to close a window in rain? (a) a distance sensor (b) a rain sensor (c) a light sensor (d) a sound sensor
33. 33.True or false: to water a dry plant, use a sound sensor. (a) False (b) True
34. 34.True or false: to measure classroom noise, use a rain sensor. (a) False (b) True
35. 35.Which job needs a temperature sensor? (a) stop a robot near walls (b) switch on lamps at dusk (c) measure classroom noise (d) start a fan when hot
36. 36.Which job needs a sound sensor? (a) water a dry plant (b) keep an incubator warm (c) start a fan when hot (d) switch on with a clap
37. 37.True or false: to water a dry plant, use a gas sensor. (a) True (b) False
38. 38.🔍 A distance sensor sends a sound pulse and hears the echo 12 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
39. 39.True or false: to measure classroom noise, use a distance sensor. (a) True (b) False
40. 40.Which job needs a servo motor? (a) turn to an exact angle (b) spin a robot’s wheels (c) move water to plants (d) show a status light

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