Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 729 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.What does a reed switch do? (a) stays where you flip it (b) springs back when let go (c) closes near a magnet (d) works only while pressed
2. 2.🌈 A resistor has the colour bands red, blue, red. What is its value (in ohms)?
3. 3.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the battery (c) the output (d) the process
4. 4.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) read the soil sensor (b) wait a few seconds (c) compare with the limit
5. 5.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
6. 6.⚠️ Is it safe to stop if a part gets hot? (a) safe (b) not safe
7. 7.⚙️ Which actuator would you use to show the temperature? (a) a servo motor (b) an LED (c) a motor (d) a display
8. 8.🔍 Which is the odd one out? (a) a metal paper clip (b) a woollen thread (c) an iron nail (d) aluminium foil
9. 9.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
10. 10.🌈 A resistor has the colour bands brown, black, red. What is its value in kilo-ohms (kΩ)? =
11. 11.True or false: a mixer grinder mainly makes sound. (a) True (b) False
12. 12.⚡ A 36 W device works on 12 V. What current does it take (in amperes)? =
13. 13.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is OFF, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
14. 14.Which of these wastes electricity? (a) use LED lamps (b) run fans in empty rooms (c) set the AC to 24 °C (d) unplug idle chargers
15. 15.📶 How many states can a digital pin have? (a) one (b) ten (c) a thousand (d) two
16. 16.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) adds 1 to count (d) prints 1
17. 17.🔁 What does a variable do in a program? (a) stores a value (b) blinks an LED (c) joins two wires (d) measures light
18. 18.⚡ A device works on 12 V and takes 1.5 A. What is its power (in watts)? =
19. 19.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
20. 20.🔋 A 12 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
21. 21.Which job is done by the power LED? (a) connect sensors and LEDs (b) keeps the voltage steady (c) shows the board is on (d) restarts the program
22. 22.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 18 Ω resistor? (a) red-grey-black (b) brown-grey-black (c) grey-brown-black (d) brown-grey-brown
24. 24.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) leave the TV on standby (d) set the AC to 24 °C
25. 25.🤖 if (temperature > 30) { fan ON } else { fan OFF }
    The temperature sensor reads 35 °C. What happens? (a) fan OFF (b) fan ON
26. 26.🔐 Is it a good or a risky habit to share only needed data? (a) good habit (b) risky habit
27. 27.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 38 °C. What is shown? (a) Hot (b) Warm (c) Cool
28. 28.💡 In a series circuit, how many paths does the current have? (a) one (b) two (c) none (d) one for each bulb
29. 29.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) wind energy (c) nuclear energy (d) electrical energy
30. 30.🤖 if (sound > 70) { red LED ON } else { green LED ON }
    The sound sensor reads 82. What happens? (a) green LED ON (b) red LED ON
31. 31.True or false: an LED glows using little power. (a) False (b) True
32. 32.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 30 °C. What happens? (a) fan OFF (b) fan ON
33. 33.🔍 Which is the odd one out? (a) a rice cooker (b) an electric iron (c) a buzzer (d) a toaster
34. 34.True or false: a reed switch works only while pressed. (a) False (b) True
35. 35.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) switch the pump on/off (b) read the soil sensor (c) wait a few seconds (d) compare with the limit
36. 36.⏱️ loop forever { LED ON; wait 950 ms; LED OFF; wait 1050 ms }
    How many times does the LED blink in 4 seconds?
37. 37.True or false: a dot where wires meet is the symbol for a wire. (a) False (b) True
38. 38.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) energy used each second (d) the colour of light
39. 39.🔌 Why are electric wires covered in plastic? (a) to make them heavy (b) plastic is an insulator (c) plastic is a conductor (d) plastic makes current
40. 40.Which of these is measured in ohms (Ω)? (a) voltage (b) resistance (c) power (d) energy used each second

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