Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 217 · 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.🔋 5 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
2. 2.Which of these is not an IoT device? (a) a Wi-Fi smart plug (b) a fitness band with app (c) a Wi-Fi weather station (d) a pencil sharpener
3. 3.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 44 °C. What is shown? (a) Cool (b) Warm (c) Hot
4. 4.🧮 Resistors of 150 Ω, 100 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
5. 5.🔌 Is a woollen thread a conductor or an insulator? (a) a conductor (b) an insulator
6. 6.🔋 5 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
7. 7.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a tilt switch
8. 8.🔌 Is a rubber eraser a conductor or an insulator? (a) a conductor (b) an insulator
9. 9.Which of these is a risky habit? (a) change default passwords (b) install software updates (c) post your live location (d) cover unused cameras
10. 10.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
11. 11.🔺 A current of 3 A flows when 18 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.🔌 Is a paper strip a conductor or an insulator? (a) a conductor (b) an insulator
13. 13.⏱️ repeat 6 times { buzzer ON; wait 600 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
14. 14.True or false: to dry your hands first is safe. (a) False (b) True
15. 15.What does a toggle switch do? (a) springs back when let go (b) flips up or down (c) closes when tipped over (d) closes near a magnet
16. 16.🔺 A current of 20 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.True or false: a circle with A inside is the symbol for an ammeter. (a) False (b) True
18. 18.True or false: a water heater mainly gives out heat. (a) False (b) True
19. 19.🧮 A 330 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
20. 20.True or false: a candle has no microcontroller inside. (a) False (b) True
21. 21.🤖 Does a hand pump usually have a microcontroller inside? (a) Yes (b) No
22. 22.What does the microcontroller do? (a) reads values, decides (b) stores data online (c) measures the real world (d) acts on a command
23. 23.True or false: to fly a kite near wires is safe. (a) False (b) True
24. 24.🔁 repeat 3 times { repeat 5 times { beep } }
    How many beeps are there?
25. 25.True or false: triangle against a bar is the symbol for a diode. (a) False (b) True
26. 26.🔐 Privacy for a smart device means controlling … (a) its colour (b) its battery size (c) who can see your data (d) how loud it beeps
27. 27.⚡ A device works on 9 V and takes 0.2 A. What is its power (in watts)? =
28. 28.🏠 Which is a smart-home example? (a) lights on from an app (b) a candle in a jar (c) a printed map (d) a hand fan
29. 29.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) switch (b) diode (c) junction (d) resistor
30. 30.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) switch (b) diode (c) junction (d) cell
31. 31.Which job is done by the power LED? (a) keeps the voltage steady (b) brings power and code (c) connect sensors and LEDs (d) shows the board is on
32. 32.🔘 A bulb and a cell are joined through 6 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
33. 33.🧮 Resistors of 20 Ω, 100 Ω, 100 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
34. 34.🔍 Which is the odd one out? (a) an LED (b) a sound sensor (c) a turning knob (d) a motion sensor
35. 35.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 100 (c) 1000 (d) 10
36. 36.True or false: to start a fan when hot, use a temperature sensor. (a) False (b) True
37. 37.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
38. 38.⚡ A 0.15 W device works on 1.5 V. What current does it take (in amperes)? =
39. 39.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
40. 40.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True

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