Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 818 · 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.🧩 Which component blows if current is high? (a) diode (b) potentiometer (c) buzzer (d) fuse
2. 2.💡 3 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
3. 3.Which drawing is the symbol for a wire? (a) a circle with A inside (b) a straight line (c) a dot where wires meet (d) a circle with M inside
4. 4.True or false: a microcontroller uses very little power. (a) False (b) True
5. 5.🔌 Which part of a screwdriver should an electrician hold? (a) the metal tip (b) the steel shaft (c) the bare end (d) the plastic handle
6. 6.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) False (b) True
7. 7.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
8. 8.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) set the AC to 24 °C (d) leave the TV on standby
9. 9.🔺 A current of 0.25 A flows when 0.5 V is joined across a resistor. What is its resistance (in ohms)?
10. 10.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
11. 11.Which of these is a conductor? (a) a dry cork (b) a woollen thread (c) a ceramic cup (d) a metal paper clip
12. 12.🧩 Which component smooths a wobbly supply? (a) LDR (b) capacitor (c) resistor (d) thermistor
13. 13.🧮 A 330 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
14. 14.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) capacitor (b) cell (c) bulb (d) motor
15. 15.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
16. 16.🔁 x = 4
    repeat 2 times { x = x × 2 }
    What is x at the end?
17. 17.⚙️ Which actuator would you use to turn to an exact angle? (a) a pump (b) a display (c) a buzzer (d) a servo motor
18. 18.Which of these is not safe? (a) stop if a part gets hot (b) stay away from pylons (c) throw cells in a fire (d) dry your hands first
19. 19.🔋 2 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
20. 20.🏠 Which is a smart-home example? (a) lights on from an app (b) a hand fan (c) a candle in a jar (d) a printed map
21. 21.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V + I (d) P = V × I
22. 22.🔦 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 graphite rod. Does the bulb glow? (a) Yes (b) No
23. 23.True or false: a steel coin is an insulator. (a) True (b) False
24. 24.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) only one (d) both of them
25. 25.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 1 minute?
26. 26.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) through a candle (c) by post (d) over Wi-Fi
27. 27.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🔍 Which is the odd one out? (a) read app permissions (b) reuse one password (c) change default passwords (d) cover unused cameras
29. 29.True or false: a push button works only while pressed. (a) False (b) True
30. 30.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
31. 31.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 1 glow? (a) No (b) Yes
32. 32.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 39 °C. What is shown? (a) Cool (b) Warm (c) Hot
33. 33.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
34. 34.What does the phone app do? (a) reads values, decides (b) acts on a command (c) shows data to you (d) carries the data
35. 35.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they all go out (c) they get dimmer (d) they keep glowing
36. 36.🔍 Which is the odd one out? (a) a buzzer beeps (b) an LED lights up (c) the pump turns on (d) a button press
37. 37.Which of these mainly gives out heat? (a) a night lamp (b) a tube light (c) an LED lamp (d) a water heater
38. 38.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 9 minutes?
39. 39.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
    How many milliseconds does one blink (ON + OFF) take?
40. 40.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) neither line (c) the shorter line (d) both lines

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