Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 229 · 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.True or false: on a cell, “the flat end” means the + (positive) end. (a) False (b) True
2. 2.🔋 2 identical 2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
3. 3.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) input (b) process (c) output
4. 4.⚠️ Why must we never touch switches with wet hands? (a) it is just untidy (b) it spoils the paint (c) water carries current (d) water makes it cold
5. 5.🔘 When a switch is ON, the circuit is … (a) broken (b) closed (c) open (d) cut
6. 6.🔍 Which is the odd one out? (a) unplug idle chargers (b) close the fridge quickly (c) use LED lamps (d) use old filament bulbs
7. 7.📏 How many ohms (Ω) is 6.5 kΩ?
8. 8.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
9. 9.🔍 Which is the odd one out? (a) a graphite rod (b) a metal paper clip (c) a copper wire (d) a plastic ruler
10. 10.🧮 Five equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
11. 11.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
12. 12.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they explode (d) they get dimmer
13. 13.True or false: a digital thermometer has no microcontroller inside. (a) True (b) False
14. 14.🧮 A 1.25 V battery is joined to 2 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
15. 15.🔢 To plan an electronics project, which comes first: “draw the circuit diagram” or “pick a problem to solve”? (a) pick a problem to solve (b) draw the circuit diagram
16. 16.⏱️ How many milliseconds is a wait of 2.3 seconds?
17. 17.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
18. 18.Which of these means the circuit is closed? (a) the switch is OFF (b) the loop is complete (c) a wire is cut (d) a cell is taken out
19. 19.💡 An LED is joined to a 6 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
20. 20.⚡ Power tells us … (a) the colour of light (b) energy used each second (c) the length of a wire (d) the size of a cell
21. 21.🔍 Which sensor would you use to keep an incubator warm? (a) a gas sensor (b) a temperature sensor (c) a sound sensor (d) a motion sensor
22. 22.🔺 A 25 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
23. 23.⏱️ A program says “wait 3250 ms”. How many seconds is that? =
24. 24.True or false: a motor blows if current is high. (a) True (b) False
25. 25.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) less than either one (d) more than either one
26. 26.True or false: to keep drinks far away is safe. (a) True (b) False
27. 27.💡 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
28. 28.🌈 In the resistor colour code, which number does brown stand for?
29. 29.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.Which of these is true of a series circuit? (a) own switch for each bulb (b) bulbs share the voltage (c) used in house wiring (d) one out, the rest glow
31. 31.🔍 Which is the odd one out? (a) a plastic ruler (b) a rubber band (c) a cotton thread (d) an iron nail
32. 32.🧩 Which component senses how bright it is? (a) LED (b) capacitor (c) LDR (d) potentiometer
33. 33.🔁 count = 9
    repeat 2 times { count = count + 6 }
    What is count at the end?
34. 34.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
35. 35.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
36. 36.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 18 °C. What is shown? (a) Hot (b) Warm (c) Cool
37. 37.True or false: a tilt switch closes when tipped over. (a) True (b) False
38. 38.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) a magnet (c) electric current (d) friction
39. 39.🧩 A capacitor in a circuit can … (a) measure heat (b) make light (c) spin a wheel (d) store charge briefly
40. 40.True or false: to climb an electric pole is safe. (a) False (b) True

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