Electronics Worksheet: Sensors and Actuators

Electronics lesson 26: Sensors and actuators · Set 228 · 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 272 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 open blinds at sunrise? (a) a light sensor (b) a sound sensor (c) a soil moisture sensor (d) a temperature sensor
3. 3.🔍 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)?
4. 4.🔍 Which sensor would you use to stop a robot near walls? (a) a gas sensor (b) a distance sensor (c) a temperature sensor (d) a soil moisture sensor
5. 5.Which job needs a temperature sensor? (a) switch on lamps at dusk (b) keep an incubator warm (c) measure classroom noise (d) warn of a gas leak
6. 6.⚙️ Which actuator would you use to spin a robot’s wheels? (a) a servo motor (b) a motor (c) an LED (d) a display
7. 7.Which job needs a buzzer? (a) show a status light (b) open a gate to 90° (c) turn to an exact angle (d) beep an alarm
8. 8.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) a fuse (c) a power source (d) an input
9. 9.⚙️ What is an actuator? (a) a program (b) a battery (c) an output that acts (d) a sensor
10. 10.Which job needs a motor? (a) show a status light (b) spin a robot’s wheels (c) beep an alarm (d) turn to an exact angle
11. 11.True or false: to make a parking alarm, use a light sensor. (a) False (b) True
12. 12.🔍 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)?
13. 13.⚙️ Which actuator would you use to move water to plants? (a) a motor (b) a pump (c) a display (d) a servo motor
14. 14.True or false: to warn of a gas leak, use a sound sensor. (a) True (b) False
15. 15.Which job needs a servo motor? (a) show the temperature (b) spin a robot’s wheels (c) open a gate to 90° (d) beep an alarm
16. 16.Which job needs an LED? (a) show a status light (b) beep an alarm (c) turn to an exact angle (d) show the temperature
17. 17.🔍 An object is 238 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
18. 18.Which job needs a light sensor? (a) open blinds at sunrise (b) keep an incubator warm (c) measure classroom noise (d) stop a robot near walls
19. 19.🔍 Which sensor would you use to water a dry plant? (a) a distance sensor (b) a gas sensor (c) a motion sensor (d) a soil moisture sensor
20. 20.⚙️ Which actuator would you use to open a gate to 90°? (a) a motor (b) a display (c) a buzzer (d) a servo motor
21. 21.Which job needs a pump? (a) show a status light (b) show the temperature (c) move water to plants (d) spin a robot’s wheels
22. 22.🔍 Which sensor would you use to switch on with a clap? (a) a temperature sensor (b) a sound sensor (c) a gas sensor (d) a soil moisture sensor
23. 23.Which job needs a gas sensor? (a) open blinds at sunrise (b) close a window in rain (c) switch on lamps at dusk (d) warn of a gas leak
24. 24.True or false: to water a dry plant, use a soil moisture sensor. (a) False (b) True
25. 25.🔍 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)?
26. 26.True or false: to close a window in rain, use a light sensor. (a) True (b) False
27. 27.Which job needs a soil moisture sensor? (a) stop a robot near walls (b) keep an incubator warm (c) water a dry plant (d) open blinds at sunrise
28. 28.True or false: to open blinds at sunrise, use a light sensor. (a) True (b) False
29. 29.True or false: to stop a robot near walls, use a soil moisture sensor. (a) True (b) False
30. 30.True or false: to warn of a gas leak, use a distance sensor. (a) False (b) True
31. 31.🔍 Which sensor would you use to make a parking alarm? (a) a temperature sensor (b) a light sensor (c) a gas sensor (d) a distance sensor
32. 32.Which job needs a motion sensor? (a) keep an incubator warm (b) close a window in rain (c) spot someone walking in (d) make a parking alarm
33. 33.🔍 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?
34. 34.Which job needs a distance sensor? (a) switch on lamps at dusk (b) keep an incubator warm (c) stop a robot near walls (d) start a fan when hot
35. 35.🔍 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?
36. 36.⚙️ Which actuator would you use to show the temperature? (a) a servo motor (b) a pump (c) a display (d) a motor
37. 37.True or false: to start a fan when hot, use a soil moisture sensor. (a) False (b) True
38. 38.True or false: to spot someone walking in, use a motion sensor. (a) False (b) True
39. 39.⚙️ Which actuator would you use to turn to an exact angle? (a) a buzzer (b) a servo motor (c) an LED (d) a display
40. 40.🔍 Which sensor would you use to measure classroom noise? (a) a distance sensor (b) a gas sensor (c) a sound sensor (d) a light sensor

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids