Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 278 · 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 136 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
2. 2.True or false: to switch on lamps at dusk, use a sound sensor. (a) True (b) False
3. 3.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) a fuse (d) an output
4. 4.Which job needs a display? (a) show a status light (b) turn to an exact angle (c) move water to plants (d) show the temperature
5. 5.Which job needs a motor? (a) spin a robot’s wheels (b) open a gate to 90° (c) show the temperature (d) move water to plants
6. 6.Which job needs a sound sensor? (a) close a window in rain (b) switch on with a clap (c) keep an incubator warm (d) start a fan when hot
7. 7.⚙️ Which actuator would you use to open a gate to 90°? (a) a motor (b) a servo motor (c) a pump (d) an LED
8. 8.Which job needs a rain sensor? (a) open blinds at sunrise (b) spot someone walking in (c) start a fan when hot (d) close a window in rain
9. 9.⚙️ Which actuator would you use to show a status light? (a) an LED (b) a pump (c) a buzzer (d) a display
10. 10.Which job needs a gas sensor? (a) warn of a gas leak (b) spot someone walking in (c) start a fan when hot (d) make a parking alarm
11. 11.⚙️ Which actuator would you use to turn to an exact angle? (a) an LED (b) a servo motor (c) a pump (d) a motor
12. 12.Which job needs a servo motor? (a) open a gate to 90° (b) beep an alarm (c) move water to plants (d) spin a robot’s wheels
13. 13.🔍 Which sensor would you use to open blinds at sunrise? (a) a rain sensor (b) a light sensor (c) a sound sensor (d) a temperature sensor
14. 14.🔍 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)?
15. 15.Which job needs a light sensor? (a) make a parking alarm (b) switch on with a clap (c) open blinds at sunrise (d) stop a robot near walls
16. 16.🔍 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?
17. 17.True or false: to make a parking alarm, use a light sensor. (a) True (b) False
18. 18.Which job needs a motion sensor? (a) spot someone walking in (b) start a fan when hot (c) switch on lamps at dusk (d) water a dry plant
19. 19.True or false: to measure classroom noise, use a sound sensor. (a) True (b) False
20. 20.⚙️ What is an actuator? (a) a battery (b) a program (c) a sensor (d) an output that acts
21. 21.True or false: to keep an incubator warm, use a temperature sensor. (a) True (b) False
22. 22.🔍 Which sensor would you use to water a dry plant? (a) a light sensor (b) a temperature sensor (c) a sound sensor (d) a soil moisture sensor
23. 23.Which job needs a light sensor? (a) keep an incubator warm (b) switch on lamps at dusk (c) spot someone walking in (d) start a fan when hot
24. 24.🔍 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 gas sensor
25. 25.🔍 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?
26. 26.Which job needs a buzzer? (a) turn to an exact angle (b) open a gate to 90° (c) spin a robot’s wheels (d) beep an alarm
27. 27.🔍 Which sensor would you use to warn of a gas leak? (a) a soil moisture sensor (b) a rain sensor (c) a sound sensor (d) a gas sensor
28. 28.🔍 A distance sensor sends a sound pulse and hears the echo 19 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
29. 29.🔍 An object is 289 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
30. 30.True or false: to open blinds at sunrise, use a gas sensor. (a) False (b) True
31. 31.True or false: to make a parking alarm, use a distance sensor. (a) False (b) True
32. 32.True or false: to close a window in rain, use a rain sensor. (a) True (b) False
33. 33.Which job needs a soil moisture sensor? (a) switch on lamps at dusk (b) warn of a gas leak (c) start a fan when hot (d) water a dry plant
34. 34.🔍 Which sensor would you use to start a fan when hot? (a) a motion sensor (b) a temperature sensor (c) a light sensor (d) a gas sensor
35. 35.🔍 Which sensor would you use to keep an incubator warm? (a) a light sensor (b) a soil moisture sensor (c) a distance sensor (d) a temperature sensor
36. 36.True or false: to start a fan when hot, use a temperature sensor. (a) True (b) False
37. 37.🔍 Which sensor would you use to make a parking alarm? (a) a gas sensor (b) a light sensor (c) a distance sensor (d) a rain sensor
38. 38.True or false: to open blinds at sunrise, use a light sensor. (a) False (b) True
39. 39.True or false: to switch on with a clap, use a sound sensor. (a) True (b) False
40. 40.🔍 Which sensor would you use to switch on lamps at dusk? (a) a temperature sensor (b) a gas sensor (c) a light sensor (d) a soil moisture sensor

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