Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 644 · 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.What does an LED do? (a) turns a fan or wheels (b) senses how bright it is (c) lets current go one way (d) glows using little power
2. 2.Which of these is an insulator? (a) a brass key (b) a safety pin (c) a steel coin (d) a rubber eraser
3. 3.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) spin a wheel (d) measure heat
4. 4.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
5. 5.🔁 repeat 4 times { repeat 5 times { beep } }
   How many beeps are there?
6. 6.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
7. 7.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
8. 8.🧮 Resistors of 470 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
9. 9.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) both lines (c) the longer line (d) neither line
10. 10.🔍 Which is the odd one out? (a) an LED lights up (b) a temperature reading (c) a soil moisture reading (d) a motion sensor signal
11. 11.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) quick and clear for all (c) symbols are heavier (d) to hide the circuit
12. 12.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) good habit (b) risky habit
13. 13.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) True (b) False
14. 14.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
15. 15.⚠️ Is it safe to poke things in a socket? (a) safe (b) not safe
16. 16.⏱️ How many milliseconds is a wait of 3.3 seconds?
17. 17.🌈 Which band is read first on a resistor? (a) the widest gap (b) the gold band (c) the one nearest an end (d) any band
18. 18.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 5 hours?
19. 19.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
20. 20.⚠️ Is it safe to climb an electric pole? (a) safe (b) not safe
21. 21.True or false: to share the Wi-Fi key is a good habit. (a) True (b) False
22. 22.🧩 Which component has coloured bands? (a) thermistor (b) resistor (c) capacitor (d) LDR
23. 23.🔘 Which kind of switch works only while pressed? (a) a reed switch (b) a push button (c) a slide switch (d) a toggle switch
24. 24.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a plastic straw. Does the bulb glow? (a) Yes (b) No
25. 25.🔌 Most metals are good … (a) magnets only (b) batteries (c) insulators (d) conductors
26. 26.⏱️ How many milliseconds is a wait of 2.7 seconds?
27. 27.🔌 A gap of dry air between two wires acts as … (a) a cell (b) an insulator (c) a switch that is ON (d) a conductor
28. 28.🧭 Which part of a microcontroller board runs the program? (a) the reset button (b) the power LED (c) the USB port (d) the main chip
29. 29.⚡ A device works on 24 V and takes 0.2 A. What is its power (in watts)? =
30. 30.💡 What does LED stand for? (a) low energy device (b) large electric dial (c) light energy dial (d) light-emitting diode
31. 31.🧮 Resistors of 100 Ω, 22 Ω, 330 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?
32. 32.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 700 ms }
    How many milliseconds does one blink (ON + OFF) take?
33. 33.🧩 Which component stores a little charge? (a) fuse (b) motor (c) LDR (d) capacitor
34. 34.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) Yes (b) No
35. 35.Which of these is an output? (a) a servo motor (b) a motion sensor (c) a light sensor (d) a keypad
36. 36.Which of these has no microcontroller inside? (a) a washing machine (b) a candle (c) a toy robot (d) a digital thermometer
37. 37.💡 An LED is joined to a 6 V battery through a 220 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) may burn out (c) lights up
38. 38.🧮 A 3 V battery is joined to 2 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
39. 39.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
    How many milliseconds does one blink (ON + OFF) take?
40. 40.🔺 A current of 20 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?

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