Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 261 · 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.Which job needs a pump? (a) open a gate to 90° (b) beep an alarm (c) turn to an exact angle (d) move water to plants
2. 2.Which of these is an IoT device? (a) a battery torch (b) a pencil sharpener (c) a plain table fan (d) a smart energy meter
3. 3.What does a slide switch do? (a) closes when tipped over (b) slides side to side (c) flips up or down (d) closes near a magnet
4. 4.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
5. 5.🧩 Which component is a resistance knob? (a) diode (b) potentiometer (c) buzzer (d) transistor
6. 6.True or false: to install software updates is a risky habit. (a) True (b) False
7. 7.🔘 Which kind of switch closes when tipped over? (a) a toggle switch (b) a slide switch (c) a tilt switch (d) a reed switch
8. 8.🔋 2 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
9. 9.🧮 Resistors of 150 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
10. 10.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
11. 11.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) friction (c) a magnet (d) electric current
12. 12.🔌 Is a safety pin a conductor or an insulator? (a) an insulator (b) a conductor
13. 13.🔺 A current of 10 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🔍 Which is the odd one out? (a) a plastic ruler (b) a steel spoon (c) a steel coin (d) a copper wire
15. 15.🔍 Which is the odd one out? (a) a smart energy meter (b) an app-controlled bulb (c) a Wi-Fi doorbell camera (d) a plain wall switch
16. 16.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) LED (b) junction (c) wire (d) cell
17. 17.🌈 Which band is read first on a resistor? (a) the gold band (b) any band (c) the one nearest an end (d) the widest gap
18. 18.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a bulb (b) a fuse or MCB (c) a long wire (d) a plug top
19. 19.🔍 Which sensor would you use to make a parking alarm? (a) a rain sensor (b) a light sensor (c) a temperature sensor (d) a distance sensor
20. 20.Which of these is true of a series circuit? (a) many paths for current (b) one bulb out, all go out (c) used in house wiring (d) own switch for each bulb
21. 21.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 27 %. What happens? (a) pump OFF (b) pump ON
22. 22.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
23. 23.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 32 °C. What is shown? (a) Warm (b) Cool (c) Hot
24. 24.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
25. 25.🤖 if (sound > 70) { red LED ON } else { green LED ON }
    The sound sensor reads 60. What happens? (a) red LED ON (b) green LED ON
26. 26.⚠️ About how many volts do home sockets in India supply? (a) 12 V (b) 230 V (c) 1.5 V (d) 9 V
27. 27.🧾 A 500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
28. 28.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 100 (c) 1000 (d) 10
29. 29.True or false: a plain rectangle is the symbol for a resistor. (a) False (b) True
30. 30.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
31. 31.🤖 Microcontroller or laptop: which one runs one small program? (a) laptop (b) microcontroller
32. 32.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) low energy device (d) large electric dial
33. 33.🧭 Which part of a microcontroller board shows the board is on? (a) the voltage regulator (b) the USB port (c) the main chip (d) the power LED
34. 34.🔐 Who should decide which smart devices go in a child’s room? (a) a parent or guardian (b) the app’s adverts (c) nobody at all (d) an online stranger
35. 35.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a paper strip across the gap. Does the bulb glow? (a) Yes (b) No
36. 36.🔁 What must there be for a current to flow? (a) a broken path (b) a complete loop (c) a plastic gap (d) one loose end
37. 37.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 4 minutes?
38. 38.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) True (b) False
39. 39.True or false: the ammeter measures voltage. (a) True (b) False
40. 40.True or false: a diode lets current go one way. (a) False (b) True

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