Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 376 · 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.🔌 Why are electric wires covered in plastic? (a) plastic is a conductor (b) to make them heavy (c) plastic makes current (d) plastic is an insulator
2. 2.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “wait a few seconds”? (a) wait a few seconds (b) read the soil sensor
3. 3.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) never (c) only when both are OFF (d) only when both are ON
4. 4.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) the board reads it (b) it is sent by Wi-Fi (c) the app shows it (d) the sensor measures
5. 5.🔁 count = 2
   while (count < 14) { count = count + 2 }
   How many times does the loop run?
6. 6.📏 How many milliamperes (mA) is 2.32 A?
7. 7.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) leave the TV on standby (d) switch off empty rooms
8. 8.🔢 To plan an electronics project, which is the FIRST step? (a) draw the circuit diagram (b) list inputs and outputs (c) test it and fix it (d) pick a problem to solve
9. 9.📶 A pin that reads a push button is set as … (a) a battery (b) a resistor (c) an output (d) an input
10. 10.Which of these is a risky habit? (a) read app permissions (b) tap unknown app links (c) share only needed data (d) log out of shared phones
11. 11.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) an LED lamp (d) a candle
12. 12.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 10 (c) 1000 (d) 100
13. 13.🔺 A current of 1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
14. 14.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
15. 15.🌐 Is a battery torch an IoT device? (a) not an IoT device (b) an IoT device
16. 16.Which of these is a good habit? (a) keep factory passwords (b) tap unknown app links (c) cover unused cameras (d) accept every permission
17. 17.🔍 Which is the odd one out? (a) a rubber band (b) a ceramic cup (c) a brass key (d) a woollen thread
18. 18.True or false: a capacitor stores a little charge. (a) False (b) True
19. 19.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a buzzer (c) a diode (d) a capacitor
20. 20.🔍 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?
21. 21.🔦 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 metal paper clip. Does the bulb glow? (a) Yes (b) No
22. 22.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
23. 23.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
24. 24.🌐 In an IoT system, which part acts on a command? (a) actuator (b) Wi-Fi (c) sensor (d) cloud server
25. 25.Which drawing is the symbol for a battery? (a) a line lifted at a gap (b) one tall, one short bar (c) many long-short pairs (d) a circle with an X in it
26. 26.🔋 5 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
27. 27.🔺 A current of 10 mA flows when 4.7 V is joined across a resistor. What is its resistance (in ohms)?
28. 28.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 1 cm. What happens? (a) buzzer beeps (b) buzzer is silent
29. 29.🔺 A current of 2 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
30. 30.💡 In a series circuit, how many paths does the current have? (a) one (b) two (c) none (d) one for each bulb
31. 31.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “test it and fix it”? (a) pick a problem to solve (b) test it and fix it
32. 32.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
33. 33.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
34. 34.Which of these is a conductor? (a) aluminium foil (b) a plastic ruler (c) a plastic straw (d) a ceramic cup
35. 35.What does a thermistor do? (a) stores a little charge (b) is a resistance knob (c) senses how hot it is (d) makes a beeping sound
36. 36.🔺 A current of 40 mA flows when 4.8 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.True or false: voltage is measured in amperes (A). (a) False (b) True
38. 38.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) No (b) Yes
39. 39.Which of these wastes electricity? (a) leave the TV on standby (b) unplug idle chargers (c) switch off empty rooms (d) use LED lamps
40. 40.Which of these mainly makes sound? (a) an electric iron (b) an electric toy car (c) a buzzer (d) an electric drill

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