Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 205 · 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 15 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
2. 2.🔍 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)?
3. 3.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a servo motor (b) a display (c) a motor (d) a pump
4. 4.⚙️ Which actuator would you use to show the temperature? (a) a display (b) a motor (c) a buzzer (d) a servo motor
5. 5.🔍 Which sensor would you use to spot someone walking in? (a) a distance sensor (b) a motion sensor (c) a light sensor (d) a temperature sensor
6. 6.⚙️ Which actuator would you use to show a status light? (a) a motor (b) an LED (c) a display (d) a servo motor
7. 7.⚙️ Which actuator would you use to open a gate to 90°? (a) a pump (b) a buzzer (c) a servo motor (d) a display
8. 8.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) a fuse (d) an output
9. 9.Which job needs a motor? (a) spin a robot’s wheels (b) show the temperature (c) open a gate to 90° (d) beep an alarm
10. 10.🔍 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)?
11. 11.Which job needs a light sensor? (a) warn of a gas leak (b) spot someone walking in (c) switch on lamps at dusk (d) switch on with a clap
12. 12.Which job needs a servo motor? (a) show a status light (b) open a gate to 90° (c) move water to plants (d) show the temperature
13. 13.Which job needs a pump? (a) turn to an exact angle (b) spin a robot’s wheels (c) move water to plants (d) show a status light
14. 14.🔍 Which sensor would you use to switch on with a clap? (a) a sound sensor (b) a motion sensor (c) a rain sensor (d) a light sensor
15. 15.🔍 Which sensor would you use to start a fan when hot? (a) a rain sensor (b) a light sensor (c) a soil moisture sensor (d) a temperature sensor
16. 16.🔍 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?
17. 17.⚙️ What is an actuator? (a) a sensor (b) a program (c) a battery (d) an output that acts
18. 18.True or false: to start a fan when hot, use a temperature sensor. (a) True (b) False
19. 19.Which job needs a rain sensor? (a) warn of a gas leak (b) stop a robot near walls (c) switch on with a clap (d) close a window in rain
20. 20.🔍 Which sensor would you use to open blinds at sunrise? (a) a temperature sensor (b) a sound sensor (c) a distance sensor (d) a light sensor
21. 21.Which job needs a servo motor? (a) show the temperature (b) spin a robot’s wheels (c) beep an alarm (d) turn to an exact angle
22. 22.🔍 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?
23. 23.🔍 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)?
24. 24.True or false: to switch on with a clap, use a sound sensor. (a) True (b) False
25. 25.🔍 An object is 85 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
26. 26.🔍 An object is 34 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
27. 27.🔍 A distance sensor sends a sound pulse and hears the echo 9 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
28. 28.Which job needs a light sensor? (a) switch on with a clap (b) warn of a gas leak (c) open blinds at sunrise (d) start a fan when hot
29. 29.🔍 Which sensor would you use to make a parking alarm? (a) a light sensor (b) a distance sensor (c) a gas sensor (d) a temperature sensor
30. 30.True or false: to make a parking alarm, use a light sensor. (a) True (b) False
31. 31.True or false: to spot someone walking in, use a sound sensor. (a) True (b) False
32. 32.Which job needs a distance sensor? (a) measure classroom noise (b) open blinds at sunrise (c) switch on with a clap (d) stop a robot near walls
33. 33.Which job needs an LED? (a) turn to an exact angle (b) spin a robot’s wheels (c) show a status light (d) move water to plants
34. 34.Which job needs a buzzer? (a) beep an alarm (b) spin a robot’s wheels (c) turn to an exact angle (d) show the temperature
35. 35.⚙️ Which actuator would you use to turn to an exact angle? (a) a pump (b) a display (c) a servo motor (d) a buzzer
36. 36.True or false: to switch on lamps at dusk, use a motion sensor. (a) True (b) False
37. 37.True or false: to switch on lamps at dusk, use a light sensor. (a) True (b) False
38. 38.🔍 Which sensor would you use to measure classroom noise? (a) a light sensor (b) a temperature sensor (c) a rain sensor (d) a sound sensor
39. 39.🔍 A distance sensor sends a sound pulse and hears the echo 3 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
40. 40.Which job needs a gas sensor? (a) switch on with a clap (b) spot someone walking in (c) close a window in rain (d) warn of a gas leak

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