Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 123 · 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.💡 In a series circuit, how many paths does the current have? (a) one (b) one for each bulb (c) two (d) none
2. 2.🔍 Which is the odd one out? (a) use mains for a project (b) throw cells in a fire (c) fly kites in open fields (d) use a cable with cuts
3. 3.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they delete the Wi-Fi (c) they change the colour (d) they fix security holes
4. 4.Which of these mainly gives out light? (a) an exhaust fan (b) a loudspeaker (c) a tube light (d) a table fan
5. 5.🌈 A resistor has the colour bands violet, green, orange. What is its value in kilo-ohms (kΩ)? =
6. 6.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) Yes (b) No
7. 7.🤖 if (moisture < 40) { pump ON } else { pump OFF }
   The soil moisture sensor reads 31 %. What happens? (a) pump ON (b) pump OFF
8. 8.💡 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?
9. 9.🔍 Which is the odd one out? (a) a temperature reading (b) an alert on the phone (c) the pump turns on (d) an LED lights up
10. 10.⚙️ Which actuator would you use to beep an alarm? (a) a pump (b) a servo motor (c) a motor (d) a buzzer
11. 11.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “wait a few seconds”? (a) wait a few seconds (b) compare with the limit
12. 12.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) spin a wheel (d) measure heat
13. 13.What does the Wi-Fi link do? (a) measures the real world (b) carries the data (c) shows data to you (d) acts on a command
14. 14.🌈 A resistor has the colour bands orange, grey, red. What is its value in kilo-ohms (kΩ)? =
15. 15.💡 6 identical bulbs are in parallel and each bulb has its own switch on its path. 5 of the switches are OFF and the rest are ON. How many bulbs glow?
16. 16.🔍 Which is the odd one out? (a) leave the TV on standby (b) iron one shirt at a time (c) switch off empty rooms (d) run fans in empty rooms
17. 17.🔌 Is a keypad an input or an output for a microcontroller? (a) input (b) output
18. 18.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) low energy device (d) large electric dial
19. 19.🔺 A current of 2 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
20. 20.🔐 Is it a good or a risky habit to set a strong password? (a) risky habit (b) good habit
21. 21.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
22. 22.Which of these is true of a parallel circuit? (a) a single current path (b) a break stops every bulb (c) bulbs share the voltage (d) many paths for current
23. 23.⏱️ A program says “wait 9750 ms”. How many seconds is that? =
24. 24.⏱️ A program says “wait 9500 ms”. How many seconds is that? =
25. 25.🔍 Which is the odd one out? (a) a fitness band with app (b) a Wi-Fi weather station (c) an app-controlled bulb (d) a plain wall switch
26. 26.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
27. 27.💡 3 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
28. 28.Which of these is an IoT device? (a) a plain table fan (b) a wind-up clock (c) a smart energy meter (d) a paper calendar
29. 29.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) the length of a wire (d) energy used each second
30. 30.📏 Voltmeter or ammeter: which one measures current? (a) ammeter (b) voltmeter
31. 31.🔍 Which is the odd one out? (a) use daylight to read (b) use old filament bulbs (c) close the fridge quickly (d) use LED lamps
32. 32.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
33. 33.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber band across the gap. Does the bulb glow? (a) No (b) Yes
34. 34.🔌 Is a motion sensor an input or an output for a microcontroller? (a) output (b) input
35. 35.🔢 To plan an electronics project, what comes right after “pick a problem to solve”? (a) draw the circuit diagram (b) list inputs and outputs (c) test it and fix it (d) build it with an adult
36. 36.🔍 A distance sensor sends a sound pulse and hears the echo 6 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
37. 37.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 63. What happens? (a) green LED ON (b) red LED ON
38. 38.⏱️ How many milliseconds is a wait of 3 seconds?
39. 39.Which of these is true of a series circuit? (a) many paths for current (b) one out, the rest glow (c) each gets the full volts (d) one bulb out, all go out
40. 40.💡 An LED is joined to a 3 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) lights up (b) does not light (c) may burn out

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