Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 311 · 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.🔋 5 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
2. 2.🤖 What is a microcontroller? (a) a type of battery (b) a computer on one chip (c) a kind of bulb (d) a big desktop computer
3. 3.🔺 A 2 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
4. 4.Which of these is the process? (a) a soil moisture reading (b) count button presses (c) a motion sensor signal (d) a buzzer beeps
5. 5.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 750 ms }
   How many times does the LED blink in 10 seconds?
6. 6.⚠️ 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) shout for an adult (d) wait and watch
7. 7.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) battery (b) resistor (c) LED (d) switch
8. 8.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) switch (b) voltmeter (c) diode (d) capacitor
9. 9.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
   How many times does the LED blink in 8 seconds?
10. 10.True or false: to spot someone walking in, use a motion sensor. (a) False (b) True
11. 11.🔌 Is a cotton thread a conductor or an insulator? (a) a conductor (b) an insulator
12. 12.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
13. 13.🤖 When the main loop of a microcontroller program ends, what happens? (a) it deletes itself (b) it starts again (c) it stops forever (d) the board breaks
14. 14.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
15. 15.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) stay the same (d) smaller
16. 16.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 5 V supply. What current flows (in mA)?
17. 17.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
18. 18.True or false: to share the Wi-Fi key is a good habit. (a) False (b) True
19. 19.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 88000 Ω resistor? (a) grey-grey-red (b) grey-grey-yellow (c) grey-grey-orange (d) grey-white-orange
20. 20.What does an LED do? (a) lets current go one way (b) smooths a wobbly supply (c) senses how hot it is (d) glows using little power
21. 21.🔐 Is it a good or a risky habit to share camera links? (a) risky habit (b) good habit
22. 22.True or false: energy used each second is measured in amperes (A). (a) True (b) False
23. 23.True or false: to ignore update messages is a risky habit. (a) True (b) False
24. 24.🔋 What is a battery? (a) one single wire (b) a switch with a lid (c) two or more cells joined (d) a kind of bulb
25. 25.Which of these is not safe? (a) touch a switch when wet (b) use small battery cells (c) dry your hands first (d) stop if a part gets hot
26. 26.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
27. 27.📶 On a 5 V board, a pin set HIGH gives about … (a) 230 V (b) 0 V (c) 50 V (d) 5 V
28. 28.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) read the soil sensor (b) wait a few seconds (c) compare with the limit (d) switch the pump on/off
29. 29.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) an open circuit (b) a parallel circuit (c) a safe circuit (d) a short circuit
30. 30.🔌 Is a metal paper clip a conductor or an insulator? (a) a conductor (b) an insulator
31. 31.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “it is sent by Wi-Fi”? (a) it is sent by Wi-Fi (b) the app shows it
32. 32.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 1000 (c) 10 (d) 100
33. 33.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a resistor (d) a capacitor
34. 34.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 38 %. What happens? (a) pump ON (b) pump OFF
35. 35.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 2 hours?
36. 36.🔍 Which is the odd one out? (a) read app permissions (b) log out of shared phones (c) share only needed data (d) keep factory passwords
37. 37.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) takes 1 away (d) prints 1
38. 38.⚙️ Which actuator would you use to show a status light? (a) an LED (b) a buzzer (c) a pump (d) a motor
39. 39.🔺 An 11.75 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
40. 40.🌈 Which band is read first on a resistor? (a) the widest gap (b) any band (c) the gold band (d) the one nearest an end

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