Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 793 · 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: a microwave oven usually has a microcontroller inside. (a) False (b) True
2. 2.🔐 Is it a good or a risky habit to keep factory passwords? (a) good habit (b) risky habit
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
4. 4.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 140 readings take?
5. 5.🔌 Is a steel coin a conductor or an insulator? (a) a conductor (b) an insulator
6. 6.🧩 Which component lets current go one way? (a) diode (b) transistor (c) fuse (d) resistor
7. 7.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
8. 8.What does a capacitor do? (a) blows if current is high (b) makes a beeping sound (c) limits the current (d) stores a little charge
9. 9.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 0 % (d) 25 %
10. 10.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
11. 11.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) zero (d) bigger
12. 12.🧭 Which part of a microcontroller board brings power and code? (a) the USB port (b) the voltage regulator (c) the power LED (d) the reset button
13. 13.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) water carries current (c) it is just untidy (d) it spoils the paint
14. 14.💡 A red LED uses 2 V and should get 25 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
15. 15.⏱️ repeat 8 times { buzzer ON; wait 100 ms; buzzer OFF; wait 600 ms }
    How many milliseconds does this take in all?
16. 16.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
17. 17.📏 Which unit measures the push of a cell? (a) volt (V) (b) ohm (Ω) (c) watt (W) (d) ampere (A)
18. 18.⏱️ repeat 5 times { buzzer ON; wait 500 ms; buzzer OFF; wait 300 ms }
    How many milliseconds does this take in all?
19. 19.True or false: to install software updates is a good habit. (a) False (b) True
20. 20.🔁 x = 4
    repeat 2 times { x = x × 2 }
    What is x at the end?
21. 21.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) a break stops every bulb (c) a single current path (d) one out, the rest glow
22. 22.Which job needs a temperature sensor? (a) spot someone walking in (b) start a fan when hot (c) measure classroom noise (d) switch on lamps at dusk
23. 23.🔋 3 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
24. 24.🔌 Is an LED an input or an output for a microcontroller? (a) input (b) output
25. 25.🗺️ Before building a project, what should you write down first? (a) the final price (b) the box colour (c) nothing at all (d) inputs and outputs
26. 26.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the gold band (c) the widest gap (d) any band
27. 27.💡 What does LED stand for? (a) large electric dial (b) light energy dial (c) low energy device (d) light-emitting diode
28. 28.🤖 Does a digital thermometer usually have a microcontroller inside? (a) Yes (b) No
29. 29.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a woollen thread across the gap. Does the bulb glow? (a) Yes (b) No
30. 30.True or false: to use LED lamps wastes electricity. (a) True (b) False
31. 31.⚡ What does an electric kettle mainly change electricity into? (a) movement (b) heat (c) sound (d) light
32. 32.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to change its colour (d) to limit the current
33. 33.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V + I (d) P = V × I
34. 34.🔘 Which kind of switch closes when tipped over? (a) a reed switch (b) a slide switch (c) a tilt switch (d) a push button
35. 35.🔦 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 steel spoon. Does the bulb glow? (a) Yes (b) No
36. 36.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) dotted circles (c) straight lines (d) little stars
37. 37.🌈 A resistor has the colour bands green, blue, red. What is its value (in ohms)?
38. 38.🔐 Is it a good or a risky habit to ignore update messages? (a) risky habit (b) good habit
39. 39.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 6 seconds?
40. 40.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series

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