Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 900 · 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.🔘 A bulb and a cell are joined through 6 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
2. 2.Which of these mainly makes sound? (a) a room heater (b) an electric iron (c) a mixer grinder (d) a doorbell
3. 3.🧩 A capacitor in a circuit can … (a) store charge briefly (b) spin a wheel (c) measure heat (d) make light
4. 4.💡 5 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 4 glow? (a) Yes (b) No
5. 5.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) a cell is taken out (d) a wire is cut
6. 6.💡 Why is house wiring done in parallel? (a) to save copper only (b) so all go off together (c) each gets full voltage (d) to make bulbs dim
7. 7.⚠️ About how many volts do home sockets in India supply? (a) 9 V (b) 12 V (c) 1.5 V (d) 230 V
8. 8.🔢 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
9. 9.⚡ A device works on 5 V and takes 0.5 A. What is its power (in watts)? =
10. 10.True or false: to keep an incubator warm, use a soil moisture sensor. (a) False (b) True
11. 11.💡 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) may burn out (b) does not light (c) lights up
12. 12.⚠️ Who should be with you when you build a circuit? (a) a younger child (b) a stranger online (c) a trusted adult (d) nobody
13. 13.🌈 A resistor has the colour bands green, violet, black. What is its value (in ohms)?
14. 14.🌐 Is a wind-up clock an IoT device? (a) an IoT device (b) not an IoT device
15. 15.🔍 Which is the odd one out? (a) throw cells in a fire (b) fly a kite near wires (c) stop if a part gets hot (d) use a cable with cuts
16. 16.⚠️ Is it safe to touch a switch when wet? (a) safe (b) not safe
17. 17.True or false: a laptop runs one small program. (a) False (b) True
18. 18.⚡ A 1.5 W device works on 3 V. What current does it take (in amperes)? =
19. 19.🔁 count = 4
    while (count < 10) { count = count + 3 }
    How many times does the loop run?
20. 20.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) low energy device (d) large electric dial
21. 21.🔺 A current of 25 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
22. 22.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
23. 23.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the widest gap (d) the one nearest an end
24. 24.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
25. 25.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
26. 26.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
27. 27.⚡ A device works on 24 V and takes 1.5 A. What is its power (in watts)? =
28. 28.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
29. 29.True or false: a reed switch closes near a magnet. (a) False (b) True
30. 30.🔁 x = 3
    repeat 3 times { x = x × 2 }
    What is x at the end?
31. 31.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
32. 32.Which of these is an IoT device? (a) a plain wall switch (b) a Wi-Fi smart plug (c) a battery torch (d) a pencil sharpener
33. 33.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) bigger (d) stay the same
34. 34.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = R ÷ I (c) V = I × R (d) V = I ÷ R
35. 35.Which of these is the input? (a) the pump turns on (b) compare with a limit (c) a button press (d) count button presses
36. 36.True or false: a spinning top usually has a microcontroller inside. (a) False (b) True
37. 37.🧮 Two resistors in parallel give a total that is … (a) their sum (b) always zero (c) less than either one (d) more than either one
38. 38.🔍 Which is the odd one out? (a) a plastic ruler (b) a rubber eraser (c) a steel spoon (d) a ceramic cup
39. 39.🔍 Which is the odd one out? (a) dry your hands first (b) stay away from pylons (c) throw cells in a fire (d) keep drinks far away
40. 40.🔐 Is it a good or a risky habit to ignore update messages? (a) good habit (b) risky habit

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