Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 80 · 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.Which job needs an LED? (a) show a status light (b) show the temperature (c) turn to an exact angle (d) open a gate to 90°
3. 3.🔍 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?
4. 4.⚙️ What is an actuator? (a) an output that acts (b) a battery (c) a program (d) a sensor
5. 5.⚙️ Which actuator would you use to show a status light? (a) a display (b) a buzzer (c) a pump (d) an LED
6. 6.⚙️ Which actuator would you use to open a gate to 90°? (a) a motor (b) an LED (c) a display (d) a servo motor
7. 7.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an output (c) an input (d) a fuse
8. 8.Which job needs a soil moisture sensor? (a) close a window in rain (b) spot someone walking in (c) make a parking alarm (d) water a dry plant
9. 9.🔍 An object is 153 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) water a dry plant (b) make a parking alarm (c) switch on lamps at dusk (d) warn of a gas leak
11. 11.⚙️ Which actuator would you use to beep an alarm? (a) a servo motor (b) an LED (c) a buzzer (d) a motor
12. 12.Which job needs a buzzer? (a) turn to an exact angle (b) open a gate to 90° (c) beep an alarm (d) spin a robot’s wheels
13. 13.🔍 A distance sensor sends a sound pulse and hears the echo 4 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
14. 14.🔍 A distance sensor sends a sound pulse and hears the echo 7 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
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 warn of a gas leak? (a) a temperature sensor (b) a sound sensor (c) a rain sensor (d) a gas sensor
17. 17.🔍 Which sensor would you use to spot someone walking in? (a) a motion sensor (b) a sound sensor (c) a soil moisture sensor (d) a temperature sensor
18. 18.Which job needs a motor? (a) spin a robot’s wheels (b) open a gate to 90° (c) move water to plants (d) beep an alarm
19. 19.Which job needs a rain sensor? (a) switch on with a clap (b) start a fan when hot (c) stop a robot near walls (d) close a window in rain
20. 20.Which job needs a motion sensor? (a) keep an incubator warm (b) close a window in rain (c) switch on with a clap (d) spot someone walking in
21. 21.🔍 Which sensor would you use to open blinds at sunrise? (a) a light sensor (b) a distance sensor (c) a sound sensor (d) a soil moisture sensor
22. 22.⚙️ Which actuator would you use to move water to plants? (a) an LED (b) a motor (c) a servo motor (d) a pump
23. 23.Which job needs a display? (a) show a status light (b) turn to an exact angle (c) spin a robot’s wheels (d) show the temperature
24. 24.True or false: to open blinds at sunrise, use a distance sensor. (a) False (b) True
25. 25.⚙️ Which actuator would you use to turn to an exact angle? (a) a servo motor (b) a pump (c) a motor (d) a display
26. 26.🔍 Which sensor would you use to start a fan when hot? (a) a rain sensor (b) a light sensor (c) a motion sensor (d) a temperature sensor
27. 27.True or false: to open blinds at sunrise, use a sound sensor. (a) True (b) False
28. 28.🔍 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?
29. 29.🔍 Which sensor would you use to measure classroom noise? (a) a light sensor (b) a rain sensor (c) a sound sensor (d) a temperature sensor
30. 30.🔍 Which sensor would you use to switch on lamps at dusk? (a) a light sensor (b) a gas sensor (c) a motion sensor (d) a distance sensor
31. 31.🔍 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?
32. 32.Which job needs a gas sensor? (a) keep an incubator warm (b) warn of a gas leak (c) open blinds at sunrise (d) stop a robot near walls
33. 33.Which job needs a sound sensor? (a) switch on with a clap (b) water a dry plant (c) keep an incubator warm (d) switch on lamps at dusk
34. 34.🔍 A distance sensor sends a sound pulse and hears the echo 17 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
35. 35.🔍 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)?
36. 36.Which job needs a distance sensor? (a) switch on lamps at dusk (b) close a window in rain (c) make a parking alarm (d) start a fan when hot
37. 37.Which job needs a distance sensor? (a) measure classroom noise (b) close a window in rain (c) switch on with a clap (d) stop a robot near walls
38. 38.🔍 Which sensor would you use to keep an incubator warm? (a) a light sensor (b) a gas sensor (c) a temperature sensor (d) a sound sensor
39. 39.🔍 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?
40. 40.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True

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