Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 230 · 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.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
2. 2.True or false: to build with an adult near is safe. (a) True (b) False
3. 3.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) blinks 500 times (c) pauses for half a second (d) turns the LED off
4. 4.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) capacitor (b) cell (c) switch (d) resistor
5. 5.🔌 Which metal is used for most electric wires at home? (a) glass (b) copper (c) rubber (d) plastic
6. 6.🔍 Which is the odd one out? (a) a plain wall switch (b) a plain table fan (c) a smart energy meter (d) a wind-up clock
7. 7.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) the else part (c) neither part (d) both parts
8. 8.⚡ A device works on 6 V and takes 0.1 A. What is its power (in watts)? =
9. 9.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 50 % (d) 5 %
10. 10.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = R ÷ V (c) I = V × R (d) I = V ÷ R
11. 11.🔍 Which is the odd one out? (a) a Wi-Fi weather station (b) a paper calendar (c) a plain wall switch (d) a battery torch
12. 12.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V + I (c) P = V ÷ I (d) P = V × I
13. 13.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) list inputs and outputs (b) build it with an adult (c) test it and fix it (d) pick a problem to solve
14. 14.🧮 A 2.2 V battery is joined to 6 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
15. 15.🔺 A current of 2 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
16. 16.True or false: to warn of a gas leak, use a gas sensor. (a) True (b) False
17. 17.🔍 Which is the odd one out? (a) a fitness band with app (b) a Wi-Fi weather station (c) a wind-up clock (d) a Wi-Fi smart plug
18. 18.What does a thermistor do? (a) senses how hot it is (b) lets current go one way (c) smooths a wobbly supply (d) limits the current
19. 19.🧮 Resistors of 10 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
20. 20.🗺️ Before building a project, what should you write down first? (a) the box colour (b) nothing at all (c) the final price (d) inputs and outputs
21. 21.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
22. 22.⚡ A device works on 3 V and takes 0.1 A. What is its power (in watts)? =
23. 23.⏱️ repeat 6 times { buzzer ON; wait 300 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
24. 24.True or false: energy used each second is measured in ohms (Ω). (a) True (b) False
25. 25.True or false: how much a part resists is measured in amperes (A). (a) False (b) True
26. 26.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the USB port (b) the main chip (c) the voltage regulator (d) the reset button
27. 27.What does a reed switch do? (a) flips up or down (b) closes when tipped over (c) closes near a magnet (d) works only while pressed
28. 28.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
29. 29.Which of these wastes electricity? (a) use LED lamps (b) leave fridge door open (c) unplug idle chargers (d) switch off empty rooms
30. 30.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 6 hours?
31. 31.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
32. 32.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “switch the pump on/off”? (a) compare with the limit (b) switch the pump on/off
33. 33.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “wait a few seconds”? (a) wait a few seconds (b) read the soil sensor
34. 34.⏱️ repeat 10 times { buzzer ON; wait 200 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
35. 35.🌈 In the resistor colour code, which number does brown stand for?
36. 36.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) voltmeter (b) ammeter (c) battery (d) motor
37. 37.True or false: a microcontroller runs many apps at once. (a) False (b) True
38. 38.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 160 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
39. 39.True or false: the voltmeter measures current. (a) False (b) True
40. 40.🔍 An object is 17 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?

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