Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 51 · 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: to touch a switch when wet is safe. (a) False (b) True
2. 2.Which of these is not safe? (a) dry your hands first (b) stay away from pylons (c) use small battery cells (d) fly a kite near wires
3. 3.🔌 Is a metal paper clip a conductor or an insulator? (a) an insulator (b) a conductor
4. 4.🔘 Which kind of switch stays where you flip it? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a tilt switch
5. 5.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) bigger (d) stay the same
6. 6.🔌 Is a sound sensor an input or an output for a microcontroller? (a) output (b) input
7. 7.🤖 Microcontroller or laptop: which one uses very little power? (a) microcontroller (b) laptop
8. 8.True or false: to build with an adult near is safe. (a) True (b) False
9. 9.🔘 Which kind of switch works only while pressed? (a) a push button (b) a slide switch (c) a toggle switch (d) a tilt switch
10. 10.📏 Which unit measures power? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
11. 11.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True
12. 12.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 13 °C. What is shown? (a) Hot (b) Cool (c) Warm
13. 13.⚡ A 24 W device works on 24 V. What current does it take (in amperes)? =
14. 14.💡 2 identical bulbs are joined in series with a 5 V battery (ideal wires). How many volts does each bulb get? =
15. 15.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
16. 16.🔋 A 6 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
17. 17.Which of these is measured in watts (W)? (a) how much a part resists (b) the push of a cell (c) energy used each second (d) voltage
18. 18.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
19. 19.🔍 Which is the odd one out? (a) use a cable with cuts (b) throw cells in a fire (c) climb an electric pole (d) use small battery cells
20. 20.🧩 Which component has coloured bands? (a) resistor (b) motor (c) buzzer (d) LED
21. 21.📶 Digital or analog: how bright a room is? (a) digital (b) analog
22. 22.🔺 A current of 10 mA flows when 3.3 V is joined across a resistor. What is its resistance (in ohms)?
23. 23.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) let strangers use it (b) tell it your passwords (c) mute it when not in use (d) put it in the bathroom
24. 24.⚠️ Which power source should children use for electronics projects? (a) a mains extension board (b) an inverter socket (c) a small battery pack (d) a wall socket
25. 25.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 30 %. What happens? (a) pump OFF (b) pump ON
26. 26.🌈 A resistor has the colour bands green, blue, red. What is its value (in ohms)?
27. 27.💡 4 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. Bulbs 1 and 4 are taken out of their holders. How many bulbs glow?
28. 28.True or false: a table fan mainly makes movement. (a) True (b) False
29. 29.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 260 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
30. 30.🔍 Which sensor would you use to start a fan when hot? (a) a soil moisture sensor (b) a distance sensor (c) a temperature sensor (d) a light sensor
31. 31.🔍 Which is the odd one out? (a) build with an adult near (b) stop if a part gets hot (c) dry your hands first (d) touch a switch when wet
32. 32.Which drawing is the symbol for a junction? (a) a long and a short line (b) triangle, bar and arrows (c) a straight line (d) a dot where wires meet
33. 33.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
34. 34.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) both parts (c) the else part (d) the if part
35. 35.🔺 A 2.5 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
36. 36.🔺 A 10 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
37. 37.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
    The temperature is 22 °C. What is shown? (a) Hot (b) Cool (c) Warm
38. 38.🧩 A capacitor in a circuit can … (a) spin a wheel (b) measure heat (c) store charge briefly (d) make light
39. 39.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the longer line (c) the shorter line (d) both lines
40. 40.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 22 °C. What is shown? (a) Hot (b) Warm (c) Cool

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