Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 405 · 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.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
2. 2.Which of these means the circuit is open? (a) all wires are joined (b) the bulb is unscrewed (c) the switch is ON (d) the loop is complete
3. 3.💡 6 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?
4. 4.🔺 A current of 40 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
5. 5.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) the widest gap (d) any band
6. 6.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) sets count to 1 (d) takes 1 away
7. 7.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a diode (c) a resistor (d) a buzzer
8. 8.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
9. 9.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
10. 10.⏱️ repeat 2 times { buzzer ON; wait 600 ms; buzzer OFF; wait 800 ms }
    How many milliseconds does this take in all?
11. 11.🔍 Which is the odd one out? (a) keep drinks far away (b) touch a fallen wire (c) fly a kite near wires (d) poke things in a socket
12. 12.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
13. 13.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) a power source (c) an output (d) an input
14. 14.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
15. 15.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a brass key across the gap. Does the bulb glow? (a) No (b) Yes
16. 16.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
17. 17.🧮 Five equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
18. 18.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the output (c) the process (d) the battery
19. 19.Which drawing is the symbol for a diode? (a) a long and a short line (b) triangle against a bar (c) a dot where wires meet (d) a plain rectangle
20. 20.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) parallel (b) series
21. 21.True or false: “a break stops every bulb” is true of a series circuit. (a) True (b) False
22. 22.Which of these is true of a series circuit? (a) many paths for current (b) one out, the rest glow (c) own switch for each bulb (d) one bulb out, all go out
23. 23.🌈 A resistor has the colour bands violet, grey, red. What is its value in kilo-ohms (kΩ)? =
24. 24.🔁 total = 0
    for i = 1 to 4 { total = total + i }
    What is total at the end?
25. 25.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) quick and clear for all (d) symbols are heavier
26. 26.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
27. 27.🌈 A resistor has the colour bands green, yellow, yellow. What is its value in kilo-ohms (kΩ)? =
28. 28.True or false: a transistor boosts a small signal. (a) True (b) False
29. 29.🔁 repeat 5 times { repeat 6 times { beep } }
    How many beeps are there?
30. 30.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 2 seconds?
31. 31.🔺 A current of 0.2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
32. 32.🔍 Which is the odd one out? (a) open a phone charger (b) stop if a part gets hot (c) climb an electric pole (d) fly a kite near wires
33. 33.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) a cell is taken out
34. 34.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
35. 35.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 6 seconds?
36. 36.🔘 When a switch is ON, the circuit is … (a) broken (b) closed (c) cut (d) open
37. 37.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) False (b) True
38. 38.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) bulb (b) motor (c) switch (d) capacitor
39. 39.🧭 Which part of a microcontroller board restarts the program? (a) the USB port (b) the power LED (c) the reset button (d) the main chip
40. 40.Which of these is the input? (a) the fan starts (b) an LED lights up (c) compare with a limit (d) a motion sensor signal

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