Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 143 · 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 12 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
2. 2.⚙️ What is an actuator? (a) an output that acts (b) a program (c) a sensor (d) a battery
3. 3.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) a power source (c) an output (d) an input
4. 4.🔍 Which sensor would you use to open blinds at sunrise? (a) a light sensor (b) a temperature sensor (c) a motion sensor (d) a gas sensor
5. 5.🔍 Which sensor would you use to measure classroom noise? (a) a rain sensor (b) a sound sensor (c) a gas sensor (d) a soil moisture sensor
6. 6.Which job needs an LED? (a) turn to an exact angle (b) beep an alarm (c) show a status light (d) spin a robot’s wheels
7. 7.Which job needs a sound sensor? (a) stop a robot near walls (b) spot someone walking in (c) warn of a gas leak (d) measure classroom noise
8. 8.Which job needs a distance sensor? (a) make a parking alarm (b) measure classroom noise (c) close a window in rain (d) switch on lamps at dusk
9. 9.⚙️ Which actuator would you use to show the temperature? (a) a motor (b) a display (c) a servo motor (d) an LED
10. 10.🔍 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?
11. 11.🔍 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?
12. 12.🔍 Which sensor would you use to warn of a gas leak? (a) a rain sensor (b) a light sensor (c) a gas sensor (d) a sound sensor
13. 13.🔍 Which sensor would you use to close a window in rain? (a) a rain sensor (b) a gas sensor (c) a sound sensor (d) a distance sensor
14. 14.True or false: to switch on with a clap, use a sound sensor. (a) True (b) False
15. 15.True or false: to make a parking alarm, use a distance sensor. (a) False (b) True
16. 16.Which job needs a motion sensor? (a) switch on lamps at dusk (b) close a window in rain (c) spot someone walking in (d) make a parking alarm
17. 17.Which job needs a pump? (a) beep an alarm (b) move water to plants (c) show the temperature (d) turn to an exact angle
18. 18.Which job needs a motor? (a) turn to an exact angle (b) beep an alarm (c) spin a robot’s wheels (d) open a gate to 90°
19. 19.Which job needs a rain sensor? (a) measure classroom noise (b) stop a robot near walls (c) open blinds at sunrise (d) close a window in rain
20. 20.🔍 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)?
21. 21.True or false: to measure classroom noise, use a sound sensor. (a) False (b) True
22. 22.⚙️ Which actuator would you use to beep an alarm? (a) an LED (b) a display (c) a pump (d) a buzzer
23. 23.🔍 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?
24. 24.⚙️ Which actuator would you use to show a status light? (a) a buzzer (b) a servo motor (c) a motor (d) an LED
25. 25.True or false: to switch on lamps at dusk, use a light sensor. (a) True (b) False
26. 26.🔍 Which sensor would you use to make a parking alarm? (a) a rain sensor (b) a light sensor (c) a distance sensor (d) a sound sensor
27. 27.True or false: to start a fan when hot, use a light sensor. (a) False (b) True
28. 28.True or false: to open blinds at sunrise, use a rain sensor. (a) True (b) False
29. 29.Which job needs a servo motor? (a) beep an alarm (b) spin a robot’s wheels (c) turn to an exact angle (d) show the temperature
30. 30.🔍 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)?
31. 31.🔍 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)?
32. 32.🔍 A distance sensor sends a sound pulse and hears the echo 10 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
33. 33.🔍 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)?
34. 34.Which job needs a sound sensor? (a) make a parking alarm (b) water a dry plant (c) open blinds at sunrise (d) switch on with a clap
35. 35.True or false: to start a fan when hot, use a temperature sensor. (a) False (b) True
36. 36.🔍 Which sensor would you use to switch on lamps at dusk? (a) a light sensor (b) a sound sensor (c) a temperature sensor (d) a motion sensor
37. 37.Which job needs a gas sensor? (a) stop a robot near walls (b) start a fan when hot (c) make a parking alarm (d) warn of a gas leak
38. 38.🔍 Which sensor would you use to start a fan when hot? (a) a sound sensor (b) a temperature sensor (c) a distance sensor (d) a soil moisture sensor
39. 39.🔍 Which sensor would you use to water a dry plant? (a) a soil moisture sensor (b) a gas sensor (c) a rain sensor (d) a sound sensor
40. 40.Which job needs a soil moisture sensor? (a) measure classroom noise (b) spot someone walking in (c) water a dry plant (d) switch on lamps at dusk

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