Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 780 · 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.📏 How many watts (W) is 0.9 kW?
2. 2.🔁 What does a variable do in a program? (a) measures light (b) stores a value (c) joins two wires (d) blinks an LED
3. 3.🔺 A current of 20 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔍 Which is the odd one out? (a) build with an adult near (b) stop if a part gets hot (c) climb an electric pole (d) stay away from pylons
5. 5.True or false: “how bright a room is” is a digital signal. (a) False (b) True
6. 6.🌈 A resistor has the colour bands grey, black, black. What is its value (in ohms)?
7. 7.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) a break stops every bulb (d) many paths for current
8. 8.🔌 Is a metal paper clip a conductor or an insulator? (a) a conductor (b) an insulator
9. 9.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
10. 10.True or false: a microcontroller has no screen of its own. (a) True (b) False
11. 11.🔍 Which is the odd one out? (a) use a cable with cuts (b) climb an electric pole (c) use mains for a project (d) stop if a part gets hot
12. 12.🧮 Resistors of 47 Ω, 50 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
13. 13.🔺 A 10 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
14. 14.Which of these is an insulator? (a) a copper wire (b) a dry cork (c) a safety pin (d) a graphite rod
15. 15.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
16. 16.True or false: a tilt switch flips up or down. (a) True (b) False
17. 17.True or false: a circle with M inside is the symbol for a motor. (a) True (b) False
18. 18.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) zero (d) stay the same
19. 19.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) an LED (d) a motor
20. 20.True or false: a motor stores a little charge. (a) True (b) False
21. 21.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) never (c) only when both are OFF (d) when either is ON
22. 22.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 4 V supply. What current flows (in mA)?
23. 23.💡 5 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
24. 24.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in series (c) in parallel (d) by Wi-Fi
25. 25.🔺 A current of 2.5 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
26. 26.💡 A red LED uses 2 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
27. 27.True or false: a push button works only while pressed. (a) True (b) False
28. 28.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
29. 29.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 55. What happens? (a) red LED ON (b) green LED ON
30. 30.Which of these is not an IoT device? (a) a smart energy meter (b) a Wi-Fi weather station (c) an app-controlled bulb (d) a wind-up clock
31. 31.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
32. 32.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
33. 33.🔢 To plan an electronics project, which comes first: “list inputs and outputs” or “pick a problem to solve”? (a) list inputs and outputs (b) pick a problem to solve
34. 34.🌈 A resistor has the colour bands white, yellow, yellow. What is its value in kilo-ohms (kΩ)? =
35. 35.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
36. 36.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
37. 37.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 32 °C. What is shown? (a) Warm (b) Hot (c) Cool
38. 38.🤖 Microcontroller or laptop: which one has no screen of its own? (a) microcontroller (b) laptop
39. 39.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
40. 40.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) cell (b) voltmeter (c) battery (d) bulb

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