Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 159 · 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 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
2. 2.🔍 Which sensor would you use to close a window in rain? (a) a motion sensor (b) a sound sensor (c) a soil moisture sensor (d) a rain sensor
3. 3.⚙️ Which actuator would you use to move water to plants? (a) a pump (b) a servo motor (c) a motor (d) an LED
4. 4.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) an input (c) a fuse (d) a power source
5. 5.Which job needs an LED? (a) open a gate to 90° (b) show a status light (c) turn to an exact angle (d) show the temperature
6. 6.🔍 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?
7. 7.Which job needs a temperature sensor? (a) start a fan when hot (b) measure classroom noise (c) make a parking alarm (d) switch on lamps at dusk
8. 8.🔍 An object is 51 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
9. 9.🔍 An object is 170 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
10. 10.Which job needs a light sensor? (a) open blinds at sunrise (b) switch on with a clap (c) make a parking alarm (d) warn of a gas leak
11. 11.Which job needs a servo motor? (a) spin a robot’s wheels (b) beep an alarm (c) move water to plants (d) turn to an exact angle
12. 12.🔍 A distance sensor sends a sound pulse and hears the echo 6 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
13. 13.True or false: to stop a robot near walls, use a distance sensor. (a) True (b) False
14. 14.🔍 Which sensor would you use to spot someone walking in? (a) a sound sensor (b) a light sensor (c) a temperature sensor (d) a motion sensor
15. 15.True or false: to make a parking alarm, use a soil moisture sensor. (a) False (b) True
16. 16.True or false: to open blinds at sunrise, use a gas sensor. (a) False (b) True
17. 17.True or false: to keep an incubator warm, use a rain sensor. (a) False (b) True
18. 18.Which job needs a rain sensor? (a) keep an incubator warm (b) close a window in rain (c) spot someone walking in (d) switch on lamps at dusk
19. 19.⚙️ Which actuator would you use to show the temperature? (a) a display (b) a motor (c) an LED (d) a pump
20. 20.Which job needs a motor? (a) spin a robot’s wheels (b) show a status light (c) turn to an exact angle (d) beep an alarm
21. 21.🔍 Which sensor would you use to open blinds at sunrise? (a) a gas sensor (b) a distance sensor (c) a light sensor (d) a temperature sensor
22. 22.🔍 Which sensor would you use to water a dry plant? (a) a sound sensor (b) a soil moisture sensor (c) a gas sensor (d) a rain sensor
23. 23.True or false: to measure classroom noise, use a motion sensor. (a) False (b) True
24. 24.⚙️ Which actuator would you use to open a gate to 90°? (a) an LED (b) a buzzer (c) a display (d) a servo motor
25. 25.True or false: to water a dry plant, use a distance sensor. (a) True (b) False
26. 26.🔍 Which sensor would you use to make a parking alarm? (a) a distance sensor (b) a motion sensor (c) a temperature sensor (d) a sound sensor
27. 27.True or false: to warn of a gas leak, use a gas sensor. (a) False (b) True
28. 28.⚙️ Which actuator would you use to beep an alarm? (a) a motor (b) an LED (c) a pump (d) a buzzer
29. 29.🔍 Which sensor would you use to warn of a gas leak? (a) a light sensor (b) a distance sensor (c) a gas sensor (d) a temperature sensor
30. 30.True or false: to spot someone walking in, use a rain sensor. (a) False (b) True
31. 31.🔍 Which sensor would you use to start a fan when hot? (a) a temperature sensor (b) a motion sensor (c) a sound sensor (d) a light sensor
32. 32.True or false: to spot someone walking in, use a motion sensor. (a) False (b) True
33. 33.🔍 A distance sensor sends a sound pulse and hears the echo 13 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
34. 34.⚙️ What is an actuator? (a) an output that acts (b) a program (c) a battery (d) a sensor
35. 35.🔍 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?
36. 36.Which job needs a temperature sensor? (a) stop a robot near walls (b) keep an incubator warm (c) switch on lamps at dusk (d) water a dry plant
37. 37.🔍 A distance sensor sends a sound pulse and hears the echo 20 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
38. 38.Which job needs a soil moisture sensor? (a) measure classroom noise (b) water a dry plant (c) warn of a gas leak (d) stop a robot near walls
39. 39.⚙️ Which actuator would you use to show a status light? (a) an LED (b) a buzzer (c) a display (d) a servo motor
40. 40.Which job needs a buzzer? (a) open a gate to 90° (b) show a status light (c) beep an alarm (d) spin a robot’s wheels

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