Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 506 · 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.🔍 Which is the odd one out? (a) a smart energy meter (b) a Wi-Fi smart plug (c) a battery torch (d) an app-controlled bulb
2. 2.Which of these usually has a microcontroller inside? (a) a spinning top (b) a hand pump (c) a wind-up toy (d) a digital alarm clock
3. 3.🔍 Which is the odd one out? (a) fly a kite near wires (b) touch a switch when wet (c) poke things in a socket (d) use small battery cells
4. 4.🧩 Which component has coloured bands? (a) resistor (b) fuse (c) transistor (d) potentiometer
5. 5.🧮 Resistors of 50 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
6. 6.🔌 Is a rubber band a conductor or an insulator? (a) a conductor (b) an insulator
7. 7.Which of these is the output? (a) the fan starts (b) a motion sensor signal (c) compare with a limit (d) a button press
8. 8.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = V + I (d) R = I ÷ V
9. 9.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pull them by the hand (b) pour water on them (c) wait and watch (d) shout for an adult
10. 10.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
11. 11.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
12. 12.🧮 A 9 V battery is joined to 8 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
13. 13.True or false: to use LED lamps wastes electricity. (a) False (b) True
14. 14.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) compare with the limit (b) wait a few seconds (c) switch the pump on/off
15. 15.True or false: to set up with a parent is a risky habit. (a) True (b) False
16. 16.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
17. 17.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I ÷ R (d) V = I × R
18. 18.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
19. 19.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) stay the same (d) smaller
20. 20.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
21. 21.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) True (b) False
22. 22.🧮 Five equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
23. 23.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 580 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
24. 24.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a diode (c) a capacitor (d) a buzzer
25. 25.True or false: voltage is measured in volts (V). (a) True (b) False
26. 26.🤖 if (light < 300) { lamp ON } else { lamp OFF }
    The light sensor reads 326. What happens? (a) lamp ON (b) lamp OFF
27. 27.🔢 To get a sensor reading onto a phone, what comes right after “it is sent by Wi-Fi”? (a) the app shows it (b) the board reads it (c) the cloud stores it (d) the sensor measures
28. 28.⚡ A device works on 5 V and takes 0.5 A. What is its power (in watts)? =
29. 29.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it changes colour (c) it does not light (d) it lights brighter
30. 30.What does a fuse do? (a) blows if current is high (b) limits the current (c) stores a little charge (d) senses how bright it is
31. 31.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 43 °C. What is shown? (a) Cool (b) Hot (c) Warm
32. 32.🔍 Which is the odd one out? (a) share camera links (b) keep factory passwords (c) set a strong password (d) tap unknown app links
33. 33.🤖 Where does the board keep its program when the power is off? (a) flash memory (b) the power LED (c) the resistor (d) the USB cable
34. 34.🌈 A resistor has the colour bands blue, orange, red. What is its value in kilo-ohms (kΩ)? =
35. 35.Which of these is the input? (a) check if temp > 30 (b) count button presses (c) an alert on the phone (d) a button press
36. 36.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 500 ms }
    How many milliseconds does one blink (ON + OFF) take?
37. 37.🔁 What must there be for a current to flow? (a) one loose end (b) a plastic gap (c) a complete loop (d) a broken path
38. 38.🧮 Resistors of 330 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?
39. 39.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) prints 1 (c) takes 1 away (d) sets count to 1
40. 40.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 5 is taken out of its holder. How many bulbs glow?

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