Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 108 · 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.True or false: “one out, the rest glow” is true of a series circuit. (a) False (b) True
2. 2.True or false: a washing machine has no microcontroller inside. (a) False (b) True
3. 3.🔢 To run one loop of a plant-watering program, which comes first: “wait a few seconds” or “read the soil sensor”? (a) read the soil sensor (b) wait a few seconds
4. 4.True or false: to dry your hands first is not safe. (a) True (b) False
5. 5.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a woollen thread. Does the bulb glow? (a) Yes (b) No
6. 6.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) never (c) when either is ON (d) when both are OFF
7. 7.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No
8. 8.🔌 Which metal is used for most electric wires at home? (a) plastic (b) glass (c) rubber (d) copper
9. 9.🔐 Is it a good or a risky habit to set up with a parent? (a) risky habit (b) good habit
10. 10.🧮 Resistors of 150 Ω, 20 Ω, 50 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
11. 11.Which of these mainly gives out heat? (a) an electric toy car (b) a room heater (c) a ceiling fan (d) a table fan
12. 12.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) to make bulbs dim (d) so all go off together
13. 13.🔺 A current of 1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
14. 14.⏱️ loop forever { LED ON; wait 1000 ms; LED OFF; wait 500 ms }
    How many milliseconds does one blink (ON + OFF) take?
15. 15.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) wait a few seconds (b) switch the pump on/off (c) read the soil sensor
16. 16.True or false: to set a strong password is a good habit. (a) False (b) True
17. 17.🔍 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)?
18. 18.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
19. 19.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
20. 20.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) dotted circles (d) wavy lines
21. 21.Which of these is a risky habit? (a) cover unused cameras (b) share the Wi-Fi key (c) install software updates (d) log out of shared phones
22. 22.True or false: a reed switch flips up or down. (a) True (b) False
23. 23.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 10 minutes?
24. 24.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) adds 1 to count (d) takes 1 away
25. 25.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) a power source (c) a fuse (d) an output
26. 26.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) more than either one (d) less than either one
27. 27.🌈 A resistor has the colour bands grey, brown, orange. What is its value in kilo-ohms (kΩ)? =
28. 28.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) True (b) False
29. 29.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) resistor (b) capacitor (c) LED (d) bulb
30. 30.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
31. 31.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
32. 32.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 33 °C. What is shown? (a) Cool (b) Warm (c) Hot
33. 33.🔘 Which kind of switch works only while pressed? (a) a reed switch (b) a toggle switch (c) a push button (d) a slide switch
34. 34.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
35. 35.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “it is sent by Wi-Fi”? (a) the app shows it (b) it is sent by Wi-Fi
36. 36.💡 6 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?
37. 37.🌐 In an IoT system, which part acts on a command? (a) sensor (b) microcontroller (c) cloud server (d) actuator
38. 38.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger
39. 39.⚡ Which formula gives electric power? (a) P = V × I (b) P = I ÷ V (c) P = V ÷ I (d) P = V + I
40. 40.🔌 Is a motion sensor an input or an output for a microcontroller? (a) input (b) output

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