Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 166 · 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.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
2. 2.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
3. 3.⚠️ Why must we never touch switches with wet hands? (a) it spoils the paint (b) water makes it cold (c) water carries current (d) it is just untidy
4. 4.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the main chip (b) the USB port (c) the voltage regulator (d) the reset button
5. 5.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1024 (b) 10 (c) 1000 (d) 100
6. 6.🔍 Which sensor would you use to spot someone walking in? (a) a light sensor (b) a sound sensor (c) a rain sensor (d) a motion sensor
7. 7.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
8. 8.📏 Which unit measures power? (a) ampere (A) (b) watt (W) (c) volt (V) (d) ohm (Ω)
9. 9.🧮 Resistors of 33 Ω, 100 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?
10. 10.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) prints 1 (d) adds 1 to count
11. 11.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
12. 12.True or false: a microcontroller uses very little power. (a) True (b) False
13. 13.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 320 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
14. 14.🔐 Which is the strongest password for a home smart camera? (a) password (b) admin (c) 123456 (d) Tiger#Lamp42!Moon
15. 15.Which job needs a distance sensor? (a) spot someone walking in (b) switch on lamps at dusk (c) make a parking alarm (d) start a fan when hot
16. 16.🔁 x = 2
    repeat 1 time { x = x × 2 }
    What is x at the end?
17. 17.True or false: “one out, the rest glow” is true of a series circuit. (a) False (b) True
18. 18.🔺 A current of 0.1 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
19. 19.Which of these is not an IoT device? (a) an app-controlled bulb (b) a Wi-Fi weather station (c) a fitness band with app (d) a battery torch
20. 20.🌈 A resistor has the colour bands grey, red, yellow. What is its value in kilo-ohms (kΩ)? =
21. 21.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) cell (b) battery (c) capacitor (d) resistor
22. 22.🔍 Which is the odd one out? (a) set up with a parent (b) share only needed data (c) cover unused cameras (d) post your live location
23. 23.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
24. 24.⚡ Power tells us … (a) the length of a wire (b) energy used each second (c) the size of a cell (d) the colour of light
25. 25.🔺 A current of 1.5 A flows when 4.5 V is joined across a resistor. What is its resistance (in ohms)?
26. 26.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
27. 27.Which of these is an insulator? (a) a steel spoon (b) a copper wire (c) a steel coin (d) a wooden stick
28. 28.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 180 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
29. 29.Which of these is a good habit? (a) install software updates (b) reuse one password (c) ignore update messages (d) tap unknown app links
30. 30.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) zero (c) smaller (d) stay the same
31. 31.💡 Why is house wiring done in parallel? (a) so all go off together (b) to save copper only (c) each gets full voltage (d) to make bulbs dim
32. 32.🌐 Is a Wi-Fi weather station an IoT device? (a) an IoT device (b) not an IoT device
33. 33.True or false: a reed switch closes near a magnet. (a) False (b) True
34. 34.📏 How many kilo-ohms (kΩ) is 7500 Ω? =
35. 35.Which of these is an IoT device? (a) a pencil sharpener (b) a plain table fan (c) a battery torch (d) a Wi-Fi smart plug
36. 36.🔺 A 3 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
37. 37.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) any band (c) the widest gap (d) the gold band
38. 38.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) False (b) True
39. 39.⏱️ repeat 10 times { buzzer ON; wait 100 ms; buzzer OFF; wait 900 ms }
    How many milliseconds does this take in all?
40. 40.🔺 A 5.5 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?

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