Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 90 · 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 289 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 warn of a gas leak? (a) a distance sensor (b) a gas sensor (c) a light sensor (d) a rain sensor
3. 3.⚙️ Which actuator would you use to beep an alarm? (a) a display (b) a buzzer (c) a servo motor (d) an LED
4. 4.🔍 An object is 323 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
5. 5.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) a power source (c) a fuse (d) an input
6. 6.True or false: to stop a robot near walls, use a rain sensor. (a) True (b) False
7. 7.⚙️ What is an actuator? (a) a battery (b) an output that acts (c) a sensor (d) a program
8. 8.Which job needs a motor? (a) beep an alarm (b) spin a robot’s wheels (c) show the temperature (d) turn to an exact angle
9. 9.⚙️ Which actuator would you use to show the temperature? (a) a servo motor (b) a buzzer (c) a display (d) a motor
10. 10.Which job needs a servo motor? (a) spin a robot’s wheels (b) show the temperature (c) open a gate to 90° (d) beep an alarm
11. 11.🔍 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)?
12. 12.🔍 A distance sensor sends a sound pulse and hears the echo 1 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
13. 13.True or false: to switch on lamps at dusk, use a temperature sensor. (a) True (b) False
14. 14.⚙️ Which actuator would you use to turn to an exact angle? (a) a pump (b) a servo motor (c) a buzzer (d) a motor
15. 15.Which job needs a gas sensor? (a) switch on lamps at dusk (b) warn of a gas leak (c) keep an incubator warm (d) close a window in rain
16. 16.⚙️ Which actuator would you use to move water to plants? (a) a servo motor (b) a display (c) a motor (d) a pump
17. 17.🔍 Which sensor would you use to switch on with a clap? (a) a soil moisture sensor (b) a temperature sensor (c) a motion sensor (d) a sound sensor
18. 18.⚙️ Which actuator would you use to show a status light? (a) a pump (b) a buzzer (c) a servo motor (d) an LED
19. 19.🔍 Which sensor would you use to make a parking alarm? (a) a rain sensor (b) a temperature sensor (c) a gas sensor (d) a distance sensor
20. 20.🔍 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?
21. 21.Which job needs an LED? (a) show the temperature (b) spin a robot’s wheels (c) show a status light (d) move water to plants
22. 22.Which job needs a buzzer? (a) move water to plants (b) beep an alarm (c) open a gate to 90° (d) show a status light
23. 23.🔍 Which sensor would you use to open blinds at sunrise? (a) a sound sensor (b) a distance sensor (c) a light sensor (d) a gas sensor
24. 24.True or false: to switch on with a clap, use a soil moisture sensor. (a) True (b) False
25. 25.🔍 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)?
26. 26.🔍 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?
27. 27.Which job needs a soil moisture sensor? (a) close a window in rain (b) warn of a gas leak (c) open blinds at sunrise (d) water a dry plant
28. 28.True or false: to open blinds at sunrise, use a light sensor. (a) True (b) False
29. 29.Which job needs a display? (a) show a status light (b) show the temperature (c) spin a robot’s wheels (d) turn to an exact angle
30. 30.🔍 Which sensor would you use to stop a robot near walls? (a) a rain sensor (b) a light sensor (c) a distance sensor (d) a motion sensor
31. 31.🔍 Which sensor would you use to start a fan when hot? (a) a gas sensor (b) a sound sensor (c) a soil moisture sensor (d) a temperature sensor
32. 32.Which job needs a motion sensor? (a) warn of a gas leak (b) stop a robot near walls (c) spot someone walking in (d) switch on with a clap
33. 33.True or false: to spot someone walking in, use a temperature sensor. (a) False (b) True
34. 34.🔍 Which sensor would you use to spot someone walking in? (a) a gas sensor (b) a sound sensor (c) a motion sensor (d) a rain sensor
35. 35.🔍 Which sensor would you use to water a dry plant? (a) a motion sensor (b) a rain sensor (c) a soil moisture sensor (d) a light sensor
36. 36.True or false: to start a fan when hot, use a temperature sensor. (a) False (b) True
37. 37.Which job needs a pump? (a) spin a robot’s wheels (b) beep an alarm (c) move water to plants (d) show the temperature
38. 38.🔍 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)?
39. 39.True or false: to warn of a gas leak, use a light sensor. (a) True (b) False
40. 40.🔍 Which sensor would you use to measure classroom noise? (a) a temperature sensor (b) a distance sensor (c) a motion sensor (d) a sound sensor

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