Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 609 · 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 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?
2. 2.Which job needs a distance sensor? (a) keep an incubator warm (b) open blinds at sunrise (c) water a dry plant (d) make a parking alarm
3. 3.🔁 count = 1
   while (count < 25) { count = count + 3 }
   How many times does the loop run?
4. 4.🗺️ Before building a project, what should you write down first? (a) inputs and outputs (b) the final price (c) nothing at all (d) the box colour
5. 5.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) zero (d) stay the same
6. 6.🔋 Does a solar panel give electricity or use electricity? (a) gives electricity (b) uses electricity
7. 7.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
   The temperature is 13 °C. What is shown? (a) Cool (b) Hot (c) Warm
8. 8.🔺 A current of 50 mA flows when 11 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.True or false: a candle has no microcontroller inside. (a) True (b) False
10. 10.True or false: “decide if soil is dry” is the input. (a) False (b) True
11. 11.True or false: the ammeter measures voltage. (a) True (b) False
12. 12.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the pins (b) the main chip (c) the reset button (d) the voltage regulator
13. 13.🔍 Which is the odd one out? (a) share only needed data (b) tap unknown app links (c) share the Wi-Fi key (d) reuse one password
14. 14.True or false: to use daylight to read saves electricity. (a) False (b) True
15. 15.🔺 A current of 10 mA flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.🔺 A current of 3 A flows when 18 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.📶 A pin set LOW gives about … (a) 5 V (b) 9 V (c) 1.5 V (d) 0 V
18. 18.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
19. 19.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) neither part (c) the else part (d) the if part
20. 20.What does the Wi-Fi link do? (a) carries the data (b) measures the real world (c) acts on a command (d) stores data online
21. 21.🌈 A resistor has the colour bands red, black, orange. What is its value (in ohms)?
22. 22.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) dotted circles (c) little stars (d) straight lines
23. 23.Which of these is not safe? (a) throw cells in a fire (b) stay away from pylons (c) dry your hands first (d) keep drinks far away
24. 24.⏱️ A program says “wait 4500 ms”. How many seconds is that? =
25. 25.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) always zero (c) their sum (d) less than either one
26. 26.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
27. 27.🔋 Does a power station give electricity or use electricity? (a) uses electricity (b) gives electricity
28. 28.🔍 A distance sensor sends a sound pulse and hears the echo 10 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
29. 29.True or false: if the loop is complete, the circuit is open and no current flows. (a) False (b) True
30. 30.Which of these is an IoT device? (a) an app-controlled bulb (b) a wind-up clock (c) a battery torch (d) a pencil sharpener
31. 31.🌈 Which band is read first on a resistor? (a) any band (b) the one nearest an end (c) the widest gap (d) the gold band
32. 32.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) a smaller voltage (c) a bigger voltage (d) the same voltage
33. 33.🔺 A current of 2 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
34. 34.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) large electric dial (d) low energy device
35. 35.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
36. 36.🔋 2 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
37. 37.🔍 Which is the odd one out? (a) dry your hands first (b) use a cable with cuts (c) stay away from pylons (d) build with an adult near
38. 38.🔁 x = 4
    repeat 2 times { x = x × 2 }
    What is x at the end?
39. 39.🔋 6 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
40. 40.Which of these is the input? (a) an LED lights up (b) decide if soil is dry (c) a soil moisture reading (d) check if temp > 30

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