Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 342 · 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 current of 3 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
2. 2.🔌 Why are electric wires covered in plastic? (a) to make them heavy (b) plastic is a conductor (c) plastic is an insulator (d) plastic makes current
3. 3.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
4. 4.Which of these is an insulator? (a) a graphite rod (b) a wooden stick (c) a metal paper clip (d) a steel coin
5. 5.🔌 Is a rubber band a conductor or an insulator? (a) an insulator (b) a conductor
6. 6.🌐 Is a plain table fan an IoT device? (a) an IoT device (b) not an IoT device
7. 7.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
8. 8.Which of these means the circuit is closed? (a) a wire is cut (b) a wire has come loose (c) all wires are joined (d) the switch is OFF
9. 9.Which of these gives us electricity? (a) a television (b) an air conditioner (c) a mobile phone (d) a battery
10. 10.What does the sensor do? (a) carries the data (b) measures the real world (c) acts on a command (d) reads values, decides
11. 11.🔍 Which is the odd one out? (a) an electric toy car (b) a night lamp (c) a ceiling fan (d) an electric drill
12. 12.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
13. 13.True or false: if a wire is cut, the circuit is closed and current flows. (a) True (b) False
14. 14.✏️ In a circuit diagram, which part is drawn as a straight line? (a) diode (b) wire (c) junction (d) motor
15. 15.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is ON, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
16. 16.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
17. 17.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
18. 18.🤖 Microcontroller or laptop: which one runs many apps at once? (a) microcontroller (b) laptop
19. 19.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
20. 20.⏱️ A program says “wait 8000 ms”. How many seconds is that? =
21. 21.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
22. 22.🔘 Which kind of switch closes when tipped over? (a) a push button (b) a reed switch (c) a tilt switch (d) a toggle switch
23. 23.📶 Digital or analog: a button: pressed or not? (a) digital (b) analog
24. 24.💡 3 identical bulbs are joined in series with a 9 V battery (ideal wires). How many volts does each bulb get? =
25. 25.🌈 A resistor has the colour bands white, brown, orange. What is its value in kilo-ohms (kΩ)? =
26. 26.True or false: to spot someone walking in, use a gas sensor. (a) True (b) False
27. 27.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) iron one shirt at a time (d) use LED lamps
28. 28.💡 4 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. Bulbs 1 and 4 are taken out of their holders. Does bulb 2 glow? (a) No (b) Yes
29. 29.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 10 °C. What is shown? (a) Warm (b) Cool (c) Hot
30. 30.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
31. 31.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) the size of a cell (d) energy used each second
32. 32.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a battery torch (c) a plain wall switch (d) a wind-up clock
33. 33.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) double the voltage (c) the same voltage (d) no voltage
34. 34.🔺 A current of 1 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
35. 35.🌐 Is a Wi-Fi weather station an IoT device? (a) not an IoT device (b) an IoT device
36. 36.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a capacitor (d) a resistor
37. 37.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
38. 38.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 9 V (c) 12 V (d) 1.5 V
39. 39.🤖 Which is a safe power source for a beginner microcontroller board? (a) a wall socket directly (b) bare mains wires (c) a 230 V cable (d) USB or a 9 V battery
40. 40.True or false: a laptop runs one small program. (a) True (b) False

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