Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 632 · 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.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V × R (c) I = V + R (d) I = V ÷ R
2. 2.📏 Which unit measures the flow of charge? (a) watt (W) (b) volt (V) (c) ohm (Ω) (d) ampere (A)
3. 3.True or false: a rice cooker mainly makes sound. (a) True (b) False
4. 4.🔐 Privacy for a smart device means controlling … (a) who can see your data (b) its battery size (c) its colour (d) how loud it beeps
5. 5.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
6. 6.💡 In a series circuit, how many paths does the current have? (a) none (b) one for each bulb (c) two (d) one
7. 7.True or false: the voltmeter is joined across a part. (a) False (b) True
8. 8.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) never (c) only when both are OFF (d) only when both are ON
9. 9.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 25 °C. What is shown? (a) Hot (b) Warm (c) Cool
10. 10.Which of these usually has a microcontroller inside? (a) a bicycle bell (b) a spinning top (c) a plain wall switch (d) a digital alarm clock
11. 11.Which job needs a display? (a) show a status light (b) move water to plants (c) turn to an exact angle (d) show the temperature
12. 12.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) no voltage (c) half the voltage (d) the same voltage
13. 13.🧮 Resistors of 50 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
14. 14.True or false: a potentiometer lets current go one way. (a) False (b) True
15. 15.📏 How many amperes (A) is 1170 mA? =
16. 16.🔘 Which kind of switch flips up or down? (a) a toggle switch (b) a reed switch (c) a slide switch (d) a push button
17. 17.💡 2 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 1 is taken out of its holder. How many bulbs glow?
18. 18.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 870 Ω resistor? (a) grey-violet-red (b) grey-violet-black (c) grey-violet-brown (d) violet-grey-brown
19. 19.🔁 repeat 4 times { repeat 4 times { beep } }
    How many beeps are there?
20. 20.⚡ Which formula gives electric power? (a) P = V × I (b) P = V + I (c) P = I ÷ V (d) P = V ÷ I
21. 21.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 2 hours?
22. 22.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “wait a few seconds”? (a) wait a few seconds (b) switch the pump on/off
23. 23.🔦 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 safety pin. Does the bulb glow? (a) Yes (b) No
24. 24.🔋 What should you do with used-up cells? (a) cut them open (b) throw them in a fire (c) give them for recycling (d) bury them in soil
25. 25.🧮 A 0.9 V battery is joined to 5 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
26. 26.🔺 A current of 40 mA flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
27. 27.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
28. 28.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) gets smaller (d) becomes zero
29. 29.True or false: an electric toy car mainly makes movement. (a) False (b) True
30. 30.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the length of a wire (d) the colour of light
31. 31.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop
32. 32.🔐 Why install updates on IoT devices? (a) they change the colour (b) they fix security holes (c) they delete the Wi-Fi (d) they make it heavier
33. 33.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a capacitor (c) a resistor (d) a diode
34. 34.🧮 Resistors of 470 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
35. 35.💡 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 2 are taken out of their holders. How many bulbs glow?
36. 36.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the main chip (b) the voltage regulator (c) the pins (d) the reset button
37. 37.🔌 Is a woollen thread a conductor or an insulator? (a) an insulator (b) a conductor
38. 38.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
39. 39.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) ammeter (b) bulb (c) cell (d) switch
40. 40.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter

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