Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 65 · 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.🔍 A distance sensor sends a sound pulse and hears the echo 9 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
2. 2.🔍 Which sensor would you use to keep an incubator warm? (a) a motion sensor (b) a soil moisture sensor (c) a temperature sensor (d) a distance sensor
3. 3.Which job needs a display? (a) show the temperature (b) turn to an exact angle (c) spin a robot’s wheels (d) open a gate to 90°
4. 4.🔍 A distance sensor sends a sound pulse and hears the echo 2 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
5. 5.True or false: to water a dry plant, use a light sensor. (a) True (b) False
6. 6.True or false: to start a fan when hot, use a distance sensor. (a) False (b) True
7. 7.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) a power source (c) a fuse (d) an input
8. 8.⚙️ What is an actuator? (a) a sensor (b) a program (c) an output that acts (d) a battery
9. 9.Which job needs a pump? (a) open a gate to 90° (b) turn to an exact angle (c) move water to plants (d) beep an alarm
10. 10.⚙️ Which actuator would you use to show the temperature? (a) a pump (b) a buzzer (c) a servo motor (d) a display
11. 11.Which job needs a motion sensor? (a) open blinds at sunrise (b) spot someone walking in (c) switch on with a clap (d) close a window in rain
12. 12.Which job needs an LED? (a) show a status light (b) beep an alarm (c) turn to an exact angle (d) show the temperature
13. 13.🔍 A distance sensor sends a sound pulse and hears the echo 16 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
14. 14.⚙️ Which actuator would you use to turn to an exact angle? (a) a servo motor (b) a motor (c) a display (d) an LED
15. 15.True or false: to spot someone walking in, use a motion sensor. (a) False (b) True
16. 16.🔍 Which sensor would you use to close a window in rain? (a) a soil moisture sensor (b) a rain sensor (c) a light sensor (d) a motion sensor
17. 17.🔍 Which sensor would you use to measure classroom noise? (a) a gas sensor (b) a soil moisture sensor (c) a temperature sensor (d) a sound sensor
18. 18.Which job needs a distance sensor? (a) switch on lamps at dusk (b) keep an incubator warm (c) make a parking alarm (d) start a fan when hot
19. 19.⚙️ Which actuator would you use to show a status light? (a) an LED (b) a buzzer (c) a pump (d) a motor
20. 20.True or false: to measure classroom noise, use a rain sensor. (a) False (b) True
21. 21.True or false: to spot someone walking in, use a soil moisture sensor. (a) True (b) False
22. 22.Which job needs a soil moisture sensor? (a) water a dry plant (b) switch on lamps at dusk (c) spot someone walking in (d) open blinds at sunrise
23. 23.🔍 An object is 17 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
24. 24.🔍 An object is 221 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
25. 25.🔍 Which sensor would you use to stop a robot near walls? (a) a light sensor (b) a motion sensor (c) a distance sensor (d) a gas sensor
26. 26.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a pump (b) a motor (c) a display (d) a servo motor
27. 27.Which job needs a light sensor? (a) stop a robot near walls (b) switch on with a clap (c) make a parking alarm (d) open blinds at sunrise
28. 28.True or false: to switch on with a clap, use a sound sensor. (a) True (b) False
29. 29.Which job needs a light sensor? (a) make a parking alarm (b) switch on lamps at dusk (c) start a fan when hot (d) spot someone walking in
30. 30.🔍 Which sensor would you use to open blinds at sunrise? (a) a motion sensor (b) a light sensor (c) a distance sensor (d) a soil moisture sensor
31. 31.True or false: to open blinds at sunrise, use a light sensor. (a) True (b) False
32. 32.True or false: to keep an incubator warm, use a soil moisture sensor. (a) False (b) True
33. 33.🔍 Which sensor would you use to warn of a gas leak? (a) a temperature sensor (b) a rain sensor (c) a gas sensor (d) a light sensor
34. 34.🔍 Which sensor would you use to spot someone walking in? (a) a distance sensor (b) a sound sensor (c) a motion sensor (d) a gas sensor
35. 35.Which job needs a gas sensor? (a) switch on with a clap (b) warn of a gas leak (c) water a dry plant (d) measure classroom noise
36. 36.Which job needs a motor? (a) open a gate to 90° (b) show a status light (c) turn to an exact angle (d) spin a robot’s wheels
37. 37.True or false: to switch on lamps at dusk, use a distance sensor. (a) False (b) True
38. 38.⚙️ Which actuator would you use to beep an alarm? (a) a servo motor (b) a buzzer (c) an LED (d) a motor
39. 39.True or false: to start a fan when hot, use a temperature sensor. (a) True (b) False
40. 40.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True

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