Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 19 · 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.🔘 When a switch is ON, the circuit is … (a) broken (b) closed (c) open (d) cut
2. 2.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
   The temperature is 37 °C. What is shown? (a) Cool (b) Hot (c) Warm
3. 3.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 110 readings take?
4. 4.🔍 Which sensor would you use to open blinds at sunrise? (a) a light sensor (b) a soil moisture sensor (c) a temperature sensor (d) a distance sensor
5. 5.True or false: to ignore update messages is a risky habit. (a) False (b) True
6. 6.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
7. 7.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) stays the same (d) becomes zero
8. 8.⚡ A 2.4 W device works on 12 V. What current does it take (in amperes)? =
9. 9.🔁 count = 4
   while (count < 20) { count = count + 4 }
   How many times does the loop run?
10. 10.Which of these is a risky habit? (a) post your live location (b) share only needed data (c) read app permissions (d) log out of shared phones
11. 11.🔁 count = 4
    while (count < 12) { count = count + 2 }
    How many times does the loop run?
12. 12.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is OFF, C is OFF and D is ON. Does the bulb glow? (a) Yes (b) No
13. 13.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
14. 14.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the loop is complete (d) a wire has come loose
15. 15.🔍 Which sensor would you use to spot someone walking in? (a) a light sensor (b) a motion sensor (c) a gas sensor (d) a rain sensor
16. 16.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = V + I (d) R = I ÷ V
17. 17.🔺 A current of 0.25 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
18. 18.🧮 Three equal 300 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
19. 19.✏️ 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
20. 20.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is OFF. Does the bulb glow? (a) Yes (b) No
21. 21.True or false: two or more cell symbols is the symbol for a bulb. (a) False (b) True
22. 22.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
23. 23.⏱️ How many milliseconds is a wait of 2.5 seconds?
24. 24.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
25. 25.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a glass marble across the gap. Does the bulb glow? (a) Yes (b) No
26. 26.💡 Why is house wiring done in parallel? (a) to save copper only (b) so all go off together (c) each gets full voltage (d) to make bulbs dim
27. 27.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
28. 28.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “the cloud stores it”? (a) the cloud stores it (b) the app shows it
29. 29.Which of these usually has a microcontroller inside? (a) a candle (b) a spinning top (c) a wind-up toy (d) a washing machine
30. 30.🔘 Which kind of switch closes when tipped over? (a) a reed switch (b) a slide switch (c) a push button (d) a tilt switch
31. 31.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 60. What happens? (a) green LED ON (b) red LED ON
32. 32.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
33. 33.Which of these is an input? (a) an LED (b) a speaker (c) a light sensor (d) a small display
34. 34.Which of these is an insulator? (a) aluminium foil (b) a brass key (c) a rubber band (d) a copper wire
35. 35.Which job needs a light sensor? (a) make a parking alarm (b) measure classroom noise (c) spot someone walking in (d) switch on lamps at dusk
36. 36.True or false: a tube light mainly makes movement. (a) True (b) False
37. 37.🔐 Is it a good or a risky habit to read app permissions? (a) risky habit (b) good habit
38. 38.Which of these mainly makes sound? (a) a loudspeaker (b) a mixer grinder (c) an LED lamp (d) a ceiling fan
39. 39.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
40. 40.Which of these is the process? (a) a button press (b) decide if soil is dry (c) an LED lights up (d) a soil moisture reading

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