Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 862 · 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: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
2. 2.🔁 count = 7
   repeat 8 times { count = count + 4 }
   What is count at the end?
3. 3.🔍 Which is the odd one out? (a) tap unknown app links (b) log out of shared phones (c) install software updates (d) read app permissions
4. 4.True or false: “an LED lights up” is the process. (a) True (b) False
5. 5.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 5 % (d) 25 %
6. 6.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
7. 7.🔺 A 24 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
8. 8.🔺 A 3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
9. 9.🔍 Which is the odd one out? (a) a plastic straw (b) a brass key (c) a plastic ruler (d) a cotton thread
10. 10.🏠 Which is a smart-home example? (a) a candle in a jar (b) a hand fan (c) a printed map (d) lights on from an app
11. 11.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) a cell is taken out (d) the switch is ON
12. 12.🧮 A 10 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
13. 13.Which of these is a risky habit? (a) read app permissions (b) cover unused cameras (c) set up with a parent (d) tap unknown app links
14. 14.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) a fuse (c) a power source (d) an input
15. 15.🔺 A current of 2.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
16. 16.What does a diode do? (a) limits the current (b) makes things spin (c) turns a fan or wheels (d) lets current go one way
17. 17.💡 2 identical bulbs are joined in series with a 5 V battery (ideal wires). How many volts does each bulb get? =
18. 18.🔁 repeat 5 times { repeat 2 times { beep } }
    How many beeps are there?
19. 19.🔍 Which is the odd one out? (a) throw cells in a fire (b) open a phone charger (c) touch a switch when wet (d) dry your hands first
20. 20.🔌 Is a cotton thread a conductor or an insulator? (a) a conductor (b) an insulator
21. 21.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a buzzer (c) a capacitor (d) a diode
22. 22.Which of these is true of a series circuit? (a) bulbs share the voltage (b) own switch for each bulb (c) many paths for current (d) one out, the rest glow
23. 23.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
24. 24.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a plug top (b) a fuse or MCB (c) a bulb (d) a long wire
25. 25.What does an LDR do? (a) turns a fan or wheels (b) blows if current is high (c) limits the current (d) senses how bright it is
26. 26.True or false: triangle against a bar is the symbol for a diode. (a) True (b) False
27. 27.🌐 Is a battery torch an IoT device? (a) not an IoT device (b) an IoT device
28. 28.🌈 A resistor has the colour bands brown, white, yellow. What is its value in kilo-ohms (kΩ)? =
29. 29.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a candle (c) an LED lamp (d) a filament bulb
30. 30.🔋 A 6 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
31. 31.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the widest gap (c) any band (d) the gold band
32. 32.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
33. 33.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = R ÷ I (c) V = I × R (d) V = I ÷ R
34. 34.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 28 °C. What happens? (a) fan OFF (b) fan ON
35. 35.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) junction (b) cell (c) diode (d) battery
37. 37.🔍 Which is the odd one out? (a) a speaker (b) a push button (c) a temperature sensor (d) a motion sensor
38. 38.True or false: a transistor beeps for an alarm. (a) False (b) True
39. 39.What does a slide switch do? (a) springs back when let go (b) stays where you flip it (c) slides side to side (d) closes when tipped over
40. 40.🌈 In the resistor colour code, which number does black stand for?

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