Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 979 · 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 small empty box is the symbol for a resistor. (a) True (b) False
2. 2.💡 Why is house wiring done in parallel? (a) so all go off together (b) each gets full voltage (c) to make bulbs dim (d) to save copper only
3. 3.🔍 Which sensor would you use to water a dry plant? (a) a motion sensor (b) a temperature sensor (c) a soil moisture sensor (d) a distance sensor
4. 4.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 7 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
5. 5.🤖 Does a digital thermometer usually have a microcontroller inside? (a) No (b) Yes
6. 6.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they explode (c) they get dimmer (d) they keep glowing
7. 7.What does a motor do? (a) makes things spin (b) makes a beeping sound (c) glows using little power (d) limits the current
8. 8.True or false: a reed switch slides side to side. (a) False (b) True
9. 9.🔌 Is a plastic straw a conductor or an insulator? (a) an insulator (b) a conductor
10. 10.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 1000 (c) 60 (d) 100
11. 11.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) False (b) True
12. 12.🔺 A 6 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
13. 13.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to change its colour (c) to make it brighter (d) to store charge
14. 14.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
15. 15.🔍 Which is the odd one out? (a) a rubber eraser (b) a woollen thread (c) a wooden stick (d) a brass key
16. 16.🔢 To plan an electronics project, which comes first: “build it with an adult” or “test it and fix it”? (a) build it with an adult (b) test it and fix it
17. 17.🔋 6 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
18. 18.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
19. 19.⏱️ How many milliseconds is a wait of 3.7 seconds?
20. 20.🔍 Which sensor would you use to keep an incubator warm? (a) a distance sensor (b) a temperature sensor (c) a soil moisture sensor (d) a motion sensor
21. 21.🔍 Which is the odd one out? (a) a metal paper clip (b) a brass key (c) a copper wire (d) a ceramic cup
22. 22.🔗 Series or parallel circuit: “each gets the full volts”? (a) parallel (b) series
23. 23.⚡ A fan changes electrical energy mainly into which kind of energy? (a) light energy (b) sound energy (c) chemical energy (d) movement energy
24. 24.📶 Digital or analog: a door: open or shut? (a) digital (b) analog
25. 25.🌈 In the resistor colour code, which number does white stand for?
26. 26.🔍 Which is the odd one out? (a) a motor (b) a motion sensor (c) a turning knob (d) a light sensor
27. 27.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 70 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
28. 28.🌈 A resistor has the colour bands red, brown, red. What is its value (in ohms)?
29. 29.⚡ Which tiny particles drift along a metal wire to carry the current? (a) electrons (b) dust particles (c) water drops (d) photons
30. 30.🔁 count = 5
    while (count < 15) { count = count + 2 }
    How many times does the loop run?
31. 31.True or false: to throw cells in a fire is not safe. (a) False (b) True
32. 32.Which drawing is the symbol for an LED? (a) triangle, bar and arrows (b) triangle against a bar (c) a circle with V inside (d) a plain rectangle
33. 33.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V ÷ I (d) R = V + I
34. 34.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 830 Ω resistor? (a) grey-orange-red (b) grey-orange-black (c) orange-grey-brown (d) grey-orange-brown
35. 35.💡 4 identical bulbs are joined in series with a 6 V battery (ideal wires). How many volts does each bulb get? =
36. 36.🌐 In an IoT system, which part stores data online? (a) microcontroller (b) cloud server (c) sensor (d) Wi-Fi
37. 37.Which drawing is the symbol for a diode? (a) a circle with V inside (b) triangle against a bar (c) one tall, one short bar (d) a line lifted at a gap
38. 38.True or false: a resistor has coloured bands. (a) False (b) True
39. 39.🔘 When a switch is ON, the circuit is … (a) closed (b) broken (c) cut (d) open
40. 40.Which of these is an insulator? (a) a safety pin (b) a steel coin (c) a glass marble (d) a copper wire

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