Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 485 · 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.Which of these is an insulator? (a) a copper wire (b) an iron nail (c) a rubber band (d) a graphite rod
2. 2.True or false: “the room temperature” is an analog signal. (a) False (b) True
3. 3.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
4. 4.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 5 V supply. What current flows (in mA)?
5. 5.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a toggle switch (c) a push button (d) a slide switch
6. 6.Which of these is true of a parallel circuit? (a) own switch for each bulb (b) a break stops every bulb (c) a single current path (d) bulbs share the voltage
7. 7.🤖 if (moisture < 30) { pump ON } else { pump OFF }
   The soil moisture sensor reads 42 %. What happens? (a) pump OFF (b) pump ON
8. 8.🔁 total = 0
   for i = 1 to 3 { total = total + i }
   What is total at the end?
9. 9.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
10. 10.🔋 Does a computer give electricity or use electricity? (a) uses electricity (b) gives electricity
11. 11.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) type it all in (c) share it with friends (d) ask a parent first
12. 12.🔁 repeat 6 times { repeat 5 times { beep } }
    How many beeps are there?
13. 13.Which job needs a distance sensor? (a) close a window in rain (b) open blinds at sunrise (c) start a fan when hot (d) stop a robot near walls
14. 14.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
15. 15.🔍 Which is the odd one out? (a) ignore update messages (b) share the Wi-Fi key (c) share only needed data (d) keep factory passwords
16. 16.True or false: a copper wire is an insulator. (a) True (b) False
17. 17.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) so all go off together (d) to make bulbs dim
18. 18.⚡ A fan changes electrical energy mainly into which kind of energy? (a) chemical energy (b) movement energy (c) light energy (d) sound energy
19. 19.🔍 Which is the odd one out? (a) a temperature reading (b) a light level reading (c) an LED lights up (d) a motion sensor signal
20. 20.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) an LED lamp (c) a candle (d) a filament bulb
21. 21.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) risky habit (b) good habit
22. 22.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) put it in the bathroom (b) mute it when not in use (c) tell it your passwords (d) let strangers use it
23. 23.Which of these mainly makes sound? (a) a water heater (b) a toaster (c) an electric toy car (d) a loudspeaker
24. 24.Which drawing is the symbol for a battery? (a) two or more cell symbols (b) triangle, bar and arrows (c) a circle with M inside (d) a circle with A inside
25. 25.🌈 In the resistor colour code, which number does red stand for?
26. 26.🔁 x = 5
    repeat 3 times { x = x × 2 }
    What is x at the end?
27. 27.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) a series circuit (d) an open circuit
28. 28.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
29. 29.Which of these means the circuit is closed? (a) a wire is cut (b) the switch is OFF (c) all wires are joined (d) the bulb is unscrewed
30. 30.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 130 readings take?
31. 31.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
32. 32.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) neither part (d) the else part
33. 33.🔋 6 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
34. 34.🌈 A resistor has the colour bands brown, black, orange. What is its value (in ohms)?
35. 35.Which of these is an output? (a) a motion sensor (b) a buzzer (c) a push button (d) a temperature sensor
36. 36.⚡ What does a table fan mainly change electricity into? (a) heat (b) movement (c) sound (d) light
37. 37.True or false: “a door: open or shut” is a digital signal. (a) False (b) True
38. 38.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a capacitor (c) a diode (d) a resistor
39. 39.💡 What happens if an LED is put in backwards? (a) it changes colour (b) it does not light (c) it makes a sound (d) it lights brighter
40. 40.⚡ What does a torch mainly change electricity into? (a) heat (b) sound (c) movement (d) light

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