Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 262 · 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: a capacitor smooths a wobbly supply. (a) False (b) True
2. 2.📏 How many watts (W) is 3.3 kW?
3. 3.🌈 A resistor has the colour bands violet, brown, red. What is its value (in ohms)?
4. 4.🔺 A current of 25 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
5. 5.What does a toggle switch do? (a) flips up or down (b) works only while pressed (c) closes when tipped over (d) closes near a magnet
6. 6.Which drawing is the symbol for a resistor? (a) a circle with a cross (b) a long and a short line (c) many long-short pairs (d) a plain rectangle
7. 7.📏 How many kilowatts (kW) is 50 W? =
8. 8.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) measure heat (d) spin a wheel
9. 9.What does a push button do? (a) springs back when let go (b) closes near a magnet (c) closes when tipped over (d) slides side to side
10. 10.⚙️ Which actuator would you use to open a gate to 90°? (a) a buzzer (b) an LED (c) a servo motor (d) a motor
11. 11.True or false: to share camera links is a good habit. (a) False (b) True
12. 12.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
13. 13.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) so all go off together (c) to save copper only (d) to make bulbs dim
14. 14.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the length of a wire (d) the colour of light
15. 15.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
16. 16.🧮 A 22 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
17. 17.🔺 A current of 0.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
18. 18.True or false: on a cell, “the flat end” means the + (positive) end. (a) True (b) False
19. 19.🧮 A 68 Ω resistor is joined in series with two equal 1000 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
20. 20.⚡ What does a toaster mainly change electricity into? (a) light (b) heat (c) sound (d) movement
21. 21.True or false: an LED lamp mainly makes sound. (a) True (b) False
22. 22.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) water makes it cold (c) water carries current (d) it spoils the paint
23. 23.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the process (c) the input (d) the battery
24. 24.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
25. 25.True or false: “the fan starts” is the input. (a) True (b) False
26. 26.Which of these is a conductor? (a) a plastic ruler (b) a steel spoon (c) a wooden stick (d) a rubber eraser
27. 27.🔢 To get a sensor reading onto a phone, which comes first: “it is sent by Wi-Fi” or “the app shows it”? (a) the app shows it (b) it is sent by Wi-Fi
28. 28.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
29. 29.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) the app shows it (b) the sensor measures (c) the cloud stores it (d) it is sent by Wi-Fi
30. 30.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
31. 31.🔁 count = 2
    while (count < 11) { count = count + 3 }
    How many times does the loop run?
32. 32.Which of these mainly gives out light? (a) a torch (b) an exhaust fan (c) a table fan (d) a mixer grinder
33. 33.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
34. 34.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) use LED lamps (d) use old filament bulbs
35. 35.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
36. 36.🧮 Three equal 150 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
37. 37.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) stores a value (d) blinks an LED
38. 38.Which of these mainly makes sound? (a) a water heater (b) a siren (c) a torch (d) an electric iron
39. 39.🔺 A current of 1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.🔍 Which is the odd one out? (a) keep drinks far away (b) climb an electric pole (c) dry your hands first (d) build with an adult near

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