Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 85 · 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.⚠️ About how many volts do home sockets in India supply? (a) 1.5 V (b) 9 V (c) 230 V (d) 12 V
2. 2.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
3. 3.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) by Wi-Fi (d) in parallel
4. 4.Which of these mainly makes movement? (a) a school bell (b) a night lamp (c) a rice cooker (d) a ceiling fan
5. 5.🔍 Which is the odd one out? (a) fly kites in open fields (b) dry your hands first (c) open a phone charger (d) stop if a part gets hot
6. 6.🧩 Which component is a resistance knob? (a) diode (b) transistor (c) potentiometer (d) LED
7. 7.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the gold band (c) any band (d) the widest gap
8. 8.True or false: a cotton thread is an insulator. (a) False (b) True
9. 9.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
10. 10.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
11. 11.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 1 glow? (a) Yes (b) No
12. 12.Which of these is an output? (a) a sound sensor (b) a temperature sensor (c) a water pump (d) a turning knob
13. 13.🔺 A 7.5 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
14. 14.📏 Voltmeter or ammeter: which one is joined in series? (a) voltmeter (b) ammeter
15. 15.True or false: an LED lamp mainly makes movement. (a) False (b) True
16. 16.🔐 Is it a good or a risky habit to set a strong password? (a) good habit (b) risky habit
17. 17.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
18. 18.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) sound energy (b) chemical energy (c) movement energy (d) light energy
19. 19.🔍 Which is the odd one out? (a) a keypad (b) a motion sensor (c) an LED (d) a temperature sensor
20. 20.🌐 How does a home IoT device usually send its data to the app? (a) through a candle (b) over Wi-Fi (c) by post (d) by shouting
21. 21.Which job needs a distance sensor? (a) stop a robot near walls (b) switch on lamps at dusk (c) keep an incubator warm (d) spot someone walking in
22. 22.📶 Digital or analog: the room temperature? (a) analog (b) digital
23. 23.True or false: to turn off unused gadgets is a risky habit. (a) True (b) False
24. 24.🔢 To get a sensor reading onto a phone, which comes first: “it is sent by Wi-Fi” or “the sensor measures”? (a) it is sent by Wi-Fi (b) the sensor measures
25. 25.🤖 if (temperature > 30) { fan ON } else { fan OFF }
    The temperature sensor reads 34 °C. What happens? (a) fan ON (b) fan OFF
26. 26.Which job needs a temperature sensor? (a) stop a robot near walls (b) keep an incubator warm (c) measure classroom noise (d) switch on with a clap
27. 27.Which of these saves electricity? (a) close the fridge quickly (b) leave the TV on standby (c) iron one shirt at a time (d) use old filament bulbs
28. 28.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) laptop (b) microcontroller
29. 29.🌈 A resistor has the colour bands orange, brown, black. What is its value (in ohms)?
30. 30.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
31. 31.True or false: to touch a switch when wet is safe. (a) True (b) False
32. 32.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
33. 33.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
34. 34.True or false: a dry cork is a conductor. (a) False (b) True
35. 35.True or false: the voltmeter measures current. (a) False (b) True
36. 36.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V + I (c) P = V × I (d) P = V ÷ I
37. 37.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a resistor (c) a diode (d) a buzzer
38. 38.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
39. 39.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = I × R (d) V = R ÷ I
40. 40.🔺 A 23.5 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?

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