Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 3 · 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.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
2. 2.Which of these usually has a microcontroller inside? (a) a smart watch (b) a spinning top (c) a hand pump (d) a bicycle bell
3. 3.Which of these is safe? (a) open a phone charger (b) use small battery cells (c) throw cells in a fire (d) poke things in a socket
4. 4.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
5. 5.📶 A pin set LOW gives about … (a) 1.5 V (b) 5 V (c) 9 V (d) 0 V
6. 6.🔋 A 3 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
7. 7.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
8. 8.🔍 Which is the odd one out? (a) count button presses (b) compare with a limit (c) check if temp > 30 (d) a buzzer beeps
9. 9.🔍 Which is the odd one out? (a) use a cable with cuts (b) fly kites in open fields (c) stay away from pylons (d) stop if a part gets hot
10. 10.💡 5 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?
11. 11.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
12. 12.💡 5 identical bulbs are joined in series with a 20 V battery (ideal wires). How many volts does each bulb get? =
13. 13.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
14. 14.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
15. 15.🧭 Which part of a microcontroller board brings power and code? (a) the voltage regulator (b) the USB port (c) the reset button (d) the main chip
16. 16.🔘 Which kind of switch closes when tipped over? (a) a push button (b) a slide switch (c) a tilt switch (d) a toggle switch
17. 17.🔺 A current of 2 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
18. 18.🔋 3 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)? =
19. 19.⚡ Power tells us … (a) the colour of light (b) energy used each second (c) the size of a cell (d) the length of a wire
20. 20.🔍 Which is the odd one out? (a) a light sensor (b) a push button (c) a small display (d) a motion sensor
21. 21.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 43. What happens? (a) green LED ON (b) red LED ON
22. 22.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
23. 23.⏱️ How many milliseconds is a wait of 3.5 seconds?
24. 24.Which of these is safe? (a) poke things in a socket (b) keep drinks far away (c) touch a switch when wet (d) climb an electric pole
25. 25.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
26. 26.🔁 count = 10
    repeat 2 times { count = count + 3 }
    What is count at the end?
27. 27.🔌 Is a woollen thread a conductor or an insulator? (a) a conductor (b) an insulator
28. 28.Which of these has no microcontroller inside? (a) a washing machine (b) a digital alarm clock (c) a toy robot (d) a candle
29. 29.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
30. 30.True or false: how much a part resists is measured in volts (V). (a) True (b) False
31. 31.True or false: “an LED lights up” is the process. (a) False (b) True
32. 32.True or false: on a cell, “the flat end” means the + (positive) end. (a) False (b) True
33. 33.🔁 repeat 4 times { repeat 2 times { beep } }
    How many beeps are there?
34. 34.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 390 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
35. 35.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) input (b) process (c) output
37. 37.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) stay the same (d) bigger
38. 38.🔺 A current of 0.25 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
39. 39.🔘 A bulb and a cell are joined through 3 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
40. 40.⚡ A device works on 3 V and takes 0.1 A. What is its power (in watts)? =

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