Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 997 · 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 is the odd one out? (a) a plastic straw (b) a cotton thread (c) a rubber eraser (d) a steel spoon
2. 2.🤖 “if (A AND B)” is true when … (a) both are false (b) only B is true (c) only A is true (d) both A and B are true
3. 3.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) to make them heavy (c) plastic is an insulator (d) plastic is a conductor
4. 4.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
5. 5.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
6. 6.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “read the soil sensor”? (a) read the soil sensor (b) compare with the limit
7. 7.True or false: a transistor makes a beeping sound. (a) True (b) False
8. 8.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) symbols are heavier (c) to make it colourful (d) quick and clear for all
9. 9.🔌 Is a water pump an input or an output for a microcontroller? (a) input (b) output
10. 10.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) their sum (c) always zero (d) more than either one
11. 11.🔺 A current of 50 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
12. 12.Which of these is safe? (a) build with an adult near (b) fly a kite near wires (c) open a phone charger (d) climb an electric pole
13. 13.True or false: a capacitor senses how hot it is. (a) False (b) True
14. 14.⏱️ A program says “wait 4500 ms”. How many seconds is that? =
15. 15.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it does not light (c) it changes colour (d) it lights brighter
16. 16.🤖 if (temperature > 30) { fan ON } else { fan OFF }
    The temperature sensor reads 37 °C. What happens? (a) fan OFF (b) fan ON
17. 17.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) True (b) False
18. 18.🌐 In an IoT system, which part measures the real world? (a) sensor (b) microcontroller (c) Wi-Fi (d) phone app
19. 19.💡 4 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
20. 20.🔍 Which sensor would you use to open blinds at sunrise? (a) a temperature sensor (b) a light sensor (c) a soil moisture sensor (d) a rain sensor
21. 21.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) friction (c) a magnet (d) electric current
22. 22.💡 6 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
23. 23.🔋 7 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)? =
24. 24.💡 5 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =
25. 25.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a glass marble across the gap. Does the bulb glow? (a) No (b) Yes
26. 26.🧮 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)?
27. 27.🔋 What should you do with used-up cells? (a) cut them open (b) bury them in soil (c) throw them in a fire (d) give them for recycling
28. 28.What does a slide switch do? (a) closes near a magnet (b) slides side to side (c) flips up or down (d) works only while pressed
29. 29.💡 An LED is joined to a 12 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) may burn out (c) does not light
30. 30.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 1.5 V (c) 230 V (d) 0.5 V
31. 31.True or false: a TV remote usually has a microcontroller inside. (a) True (b) False
32. 32.🧩 Which component senses how bright it is? (a) fuse (b) transistor (c) LDR (d) LED
33. 33.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 0 % (c) 25 % (d) 50 %
34. 34.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
35. 35.⏱️ A program says “wait 5500 ms”. How many seconds is that? =
36. 36.🔘 Which kind of switch flips up or down? (a) a reed switch (b) a tilt switch (c) a push button (d) a toggle switch
37. 37.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 1 second?
38. 38.📏 In the water-pipe picture of a circuit, resistance is like … (a) the flow of water (b) a bigger tank (c) the water pressure (d) a narrow pipe
39. 39.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) neither line (c) the longer line (d) the shorter line
40. 40.What does a reed switch do? (a) slides side to side (b) flips up or down (c) closes when tipped over (d) closes near a magnet

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