Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 459 · 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 0.2 A flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
2. 2.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V × I (d) P = V + I
3. 3.Which job needs a temperature sensor? (a) measure classroom noise (b) switch on with a clap (c) water a dry plant (d) start a fan when hot
4. 4.Which of these is an insulator? (a) a ceramic cup (b) aluminium foil (c) a copper wire (d) an iron nail
5. 5.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
6. 6.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 450 ms }
   How many times does the LED blink in 9 seconds?
7. 7.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
8. 8.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 27 °C. What is shown? (a) Hot (b) Warm (c) Cool
9. 9.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
10. 10.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) turns the LED off (c) blinks 500 times (d) waits 500 seconds
11. 11.True or false: two equal parallel lines is the symbol for a capacitor. (a) True (b) False
12. 12.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 60 (c) 100 (d) 1000
13. 13.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a long wire (b) a plug top (c) a bulb (d) a fuse or MCB
14. 14.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the main chip (b) the pins (c) the reset button (d) the voltage regulator
15. 15.Which of these is true of a parallel circuit? (a) a single current path (b) a break stops every bulb (c) one out, the rest glow (d) one bulb out, all go out
16. 16.True or false: “one out, the rest glow” is true of a series circuit. (a) True (b) False
17. 17.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) light energy (b) chemical energy (c) sound energy (d) movement energy
18. 18.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 10 (b) 100 (c) 1000 (d) 1024
19. 19.Which of these is a good habit? (a) keep factory passwords (b) change default passwords (c) reuse one password (d) share camera links
20. 20.Which of these has no microcontroller inside? (a) a candle (b) a toy robot (c) a TV remote (d) a microwave oven
21. 21.True or false: voltage is measured in volts (V). (a) False (b) True
22. 22.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) − (negative) (b) + (positive)
23. 23.🔁 count = 10
    repeat 2 times { count = count + 2 }
    What is count at the end?
24. 24.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 63 Ω resistor? (a) blue-orange-brown (b) violet-orange-black (c) blue-orange-black (d) orange-blue-black
25. 25.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) True (b) False
26. 26.⚡ A device works on 1.5 V and takes 2 A. What is its power (in watts)? =
27. 27.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 42 °C. What is shown? (a) Hot (b) Warm (c) Cool
28. 28.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “test it and fix it”? (a) pick a problem to solve (b) test it and fix it
29. 29.🔍 Which is the odd one out? (a) an alert on the phone (b) the pump turns on (c) a temperature reading (d) the fan starts
30. 30.🔌 Is a rubber band a conductor or an insulator? (a) a conductor (b) an insulator
31. 31.📏 How many watts (W) is 0.5 kW?
32. 32.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
33. 33.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
34. 34.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 96. What happens? (a) green LED ON (b) red LED ON
35. 35.🔍 Which is the odd one out? (a) an electric drill (b) a mixer grinder (c) an electric toy car (d) a rice cooker
36. 36.🌐 Is a plain wall switch an IoT device? (a) an IoT device (b) not an IoT device
37. 37.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) symbols are heavier (c) quick and clear for all (d) to make it colourful
38. 38.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
39. 39.Which drawing is the symbol for a switch? (a) many long-short pairs (b) one tall, one short bar (c) a line lifted at a gap (d) a circle with M inside
40. 40.⚡ A device works on 3 V and takes 0.25 A. What is its power (in watts)? =

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