Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 198 · 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.📶 How many states can a digital pin have? (a) one (b) two (c) ten (d) a thousand
2. 2.🧩 Which component makes things spin? (a) thermistor (b) transistor (c) motor (d) LDR
3. 3.📏 How many kilowatts (kW) is 1850 W? =
4. 4.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
5. 5.🌈 In the resistor colour code, which number does violet stand for?
6. 6.💡 5 identical bulbs are joined in series with a 15 V battery (ideal wires). How many volts does each bulb get? =
7. 7.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an oil lamp (c) a candle (d) an LED lamp
8. 8.Which of these is the process? (a) a button press (b) a motion sensor signal (c) decide if soil is dry (d) an alert on the phone
9. 9.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 22 Ω resistor? (a) orange-red-black (b) red-orange-black (c) red-red-black (d) red-red-brown
10. 10.🌈 A resistor has the colour bands violet, black, red. What is its value (in ohms)?
11. 11.🗺️ In an input → process → output plan, is “the fan starts” the input, the process or the output? (a) output (b) input (c) process
12. 12.Which job needs a temperature sensor? (a) warn of a gas leak (b) spot someone walking in (c) start a fan when hot (d) open blinds at sunrise
13. 13.Which of these is true of a parallel circuit? (a) used in house wiring (b) a single current path (c) one bulb out, all go out (d) bulbs share the voltage
14. 14.⏱️ loop forever { LED ON; wait 800 ms; LED OFF; wait 800 ms }
    How many milliseconds does one blink (ON + OFF) take?
15. 15.🤖 Which is a safe power source for a beginner microcontroller board? (a) bare mains wires (b) a wall socket directly (c) a 230 V cable (d) USB or a 9 V battery
16. 16.🧮 Two resistors in parallel give a total that is … (a) always zero (b) more than either one (c) their sum (d) less than either one
17. 17.🔍 Which is the odd one out? (a) an electric iron (b) a room heater (c) a doorbell (d) a toaster
18. 18.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is OFF and B is OFF. Does the bulb glow? (a) No (b) Yes
19. 19.🔐 Is it a good or a risky habit to log out of shared phones? (a) good habit (b) risky habit
20. 20.True or false: to use LED lamps saves electricity. (a) True (b) False
21. 21.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
22. 22.⏱️ repeat 7 times { buzzer ON; wait 200 ms; buzzer OFF; wait 1000 ms }
    How many milliseconds does this take in all?
23. 23.🔘 Which kind of switch works only while pressed? (a) a tilt switch (b) a push button (c) a toggle switch (d) a reed switch
24. 24.🔘 Which kind of switch closes near a magnet? (a) a tilt switch (b) a slide switch (c) a toggle switch (d) a reed switch
25. 25.Which of these is true of a series circuit? (a) one out, the rest glow (b) bulbs share the voltage (c) used in house wiring (d) many paths for current
26. 26.🔍 Which is the odd one out? (a) leave fridge door open (b) use old filament bulbs (c) run fans in empty rooms (d) use LED lamps
27. 27.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the else part (c) both parts (d) the if part
28. 28.True or false: a graphite rod is an insulator. (a) False (b) True
29. 29.🔐 Privacy for a smart device means controlling … (a) who can see your data (b) its colour (c) its battery size (d) how loud it beeps
30. 30.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 350 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
31. 31.Which of these is safe? (a) touch a fallen wire (b) stop if a part gets hot (c) touch a switch when wet (d) poke things in a socket
32. 32.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 560 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
33. 33.Which of these is true of a series circuit? (a) each gets the full volts (b) own switch for each bulb (c) one out, the rest glow (d) a single current path
34. 34.🧭 Which part of a microcontroller board restarts the program? (a) the voltage regulator (b) the USB port (c) the pins (d) the reset button
35. 35.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
36. 36.🤖 “if (A AND B)” is true when … (a) only B is true (b) only A is true (c) both A and B are true (d) both are false
37. 37.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 7 seconds?
38. 38.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True
39. 39.What does the Wi-Fi link do? (a) acts on a command (b) stores data online (c) carries the data (d) shows data to you
40. 40.🌈 In the resistor colour code, which number does red stand for?

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