Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 181 · 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.⏱️ A program says “wait 250 ms”. How many seconds is that? =
2. 2.🔁 x = 2
   repeat 2 times { x = x × 2 }
   What is x at the end?
3. 3.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
4. 4.True or false: a capacitor smooths a wobbly supply. (a) True (b) False
5. 5.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 2 glow? (a) No (b) Yes
6. 6.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) process (b) input (c) output
7. 7.🌈 In the resistor colour code, which number does yellow stand for?
8. 8.⚡ A device works on 5 V and takes 3 A. What is its power (in watts)? =
9. 9.💡 A battery lights 2 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
10. 10.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) a resistor (d) an LED
11. 11.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it lights brighter (c) it changes colour (d) it does not light
12. 12.🔁 count = 0
    while (count < 15) { count = count + 5 }
    How many times does the loop run?
13. 13.📏 How many milliamperes (mA) is 2.12 A?
14. 14.⚠️ Is it safe to keep drinks far away? (a) not safe (b) safe
15. 15.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) stay the same (d) bigger
16. 16.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put an iron nail across the gap. Does the bulb glow? (a) No (b) Yes
17. 17.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 200 ms }
    How many milliseconds does one blink (ON + OFF) take?
18. 18.💡 5 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
19. 19.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
20. 20.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
21. 21.⏱️ repeat 8 times { buzzer ON; wait 200 ms; buzzer OFF; wait 300 ms }
    How many milliseconds does this take in all?
22. 22.🔘 Which kind of switch closes when tipped over? (a) a slide switch (b) a reed switch (c) a tilt switch (d) a toggle switch
23. 23.🔋 4 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
24. 24.⚡ A 2.4 W device works on 24 V. What current does it take (in amperes)? =
25. 25.⏱️ How many milliseconds is a wait of 5 seconds?
26. 26.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
27. 27.🔐 Which is the strongest password for a home smart camera? (a) password (b) 123456 (c) admin (d) Tiger#Lamp42!Moon
28. 28.Which drawing is the symbol for a battery? (a) a circle with V inside (b) two or more cell symbols (c) a dot where wires meet (d) a long and a short line
29. 29.🌈 A resistor has the colour bands brown, black, red. What is its value in kilo-ohms (kΩ)? =
30. 30.🔍 Which is the odd one out? (a) the fan starts (b) decide if soil is dry (c) check if temp > 30 (d) count button presses
31. 31.True or false: “a temperature reading” is the input. (a) True (b) False
32. 32.Which job needs a gas sensor? (a) make a parking alarm (b) water a dry plant (c) close a window in rain (d) warn of a gas leak
33. 33.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 8 seconds?
34. 34.True or false: the ammeter is joined across a part. (a) True (b) False
35. 35.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) over Wi-Fi (c) by post (d) through a candle
36. 36.🔺 A current of 2.5 A flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
38. 38.Which of these is true of a series circuit? (a) one out, the rest glow (b) used in house wiring (c) bulbs share the voltage (d) many paths for current
39. 39.🤖 “if (A AND B)” is true when … (a) only B is true (b) both are false (c) both A and B are true (d) only A is true
40. 40.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No

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