Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 845 · 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.🔢 To plan an electronics project, which comes first: “build it with an adult” or “pick a problem to solve”? (a) pick a problem to solve (b) build it with an adult
2. 2.🧮 A 3.5 V battery is joined to 3 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
3. 3.🔺 A current of 3 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔘 Which kind of switch works only while pressed? (a) a slide switch (b) a toggle switch (c) a push button (d) a reed switch
5. 5.🔁 x = 3
   repeat 1 time { x = x × 2 }
   What is x at the end?
6. 6.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) each gets full voltage (c) so all go off together (d) to save copper only
7. 7.🔋 How many 1.5 V cells must be joined in series to give 10.5 V?
8. 8.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 23 °C. What is shown? (a) Warm (b) Hot (c) Cool
9. 9.What does the microcontroller do? (a) carries the data (b) reads values, decides (c) acts on a command (d) shows data to you
10. 10.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) capacitor (b) battery (c) diode (d) ammeter
11. 11.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
12. 12.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
13. 13.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
14. 14.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) neither part (d) the if part
15. 15.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True
16. 16.True or false: a microcontroller runs many apps at once. (a) False (b) True
17. 17.💡 A red LED uses 2 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
18. 18.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
19. 19.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) No (b) Yes
20. 20.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
21. 21.🔍 For a microcontroller, is a sensor an input or an output? (a) an output (b) a power source (c) a fuse (d) an input
22. 22.🤖 What is a microcontroller? (a) a kind of bulb (b) a computer on one chip (c) a big desktop computer (d) a type of battery
23. 23.🔺 A 9.4 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
24. 24.💡 3 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
25. 25.📏 How many ohms (Ω) is 7.1 kΩ?
26. 26.Which of these uses electricity? (a) a cell (b) a bicycle dynamo (c) a computer (d) a battery
27. 27.🔍 Which is the odd one out? (a) change default passwords (b) post your live location (c) read app permissions (d) share only needed data
28. 28.🧭 Which part of a microcontroller board restarts the program? (a) the main chip (b) the USB port (c) the reset button (d) the voltage regulator
29. 29.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) microcontroller (b) laptop
30. 30.🌈 A resistor has the colour bands yellow, grey, orange. What is its value in kilo-ohms (kΩ)? =
31. 31.🔍 Which is the odd one out? (a) a wooden stick (b) an iron nail (c) a steel coin (d) a metal paper clip
32. 32.🔢 To plan an electronics project, which is the FIRST step? (a) build it with an adult (b) test it and fix it (c) pick a problem to solve (d) draw the circuit diagram
33. 33.True or false: a water heater mainly gives out heat. (a) False (b) True
34. 34.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) unplug idle chargers (d) iron one shirt at a time
35. 35.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
36. 36.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
37. 37.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
38. 38.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) adds 1 to count (d) takes 1 away
39. 39.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a wall socket (c) a small battery pack (d) a mains extension board
40. 40.🧮 Resistors of 50 Ω, 150 Ω, 33 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?

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