Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 557 · 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) cover unused cameras (b) share only needed data (c) install software updates (d) reuse one password
2. 2.🔺 A 30 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
3. 3.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
4. 4.True or false: “a soil moisture reading” is the input. (a) True (b) False
5. 5.⏱️ repeat 6 times { buzzer ON; wait 600 ms; buzzer OFF; wait 900 ms }
   How many milliseconds does this take in all?
6. 6.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
7. 7.🔁 x = 4
   repeat 1 time { x = x × 2 }
   What is x at the end?
8. 8.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in parallel (c) by Wi-Fi (d) in series
9. 9.⏱️ repeat 3 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 200 ms }
   How many milliseconds does this take in all?
10. 10.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) their sum (c) always zero (d) more than either one
11. 11.🌐 In an IoT system, which part carries the data? (a) actuator (b) microcontroller (c) Wi-Fi (d) sensor
12. 12.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “the board reads it”? (a) the app shows it (b) the board reads it
13. 13.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 1700 ms }
    How many times does the LED blink in 16 seconds?
14. 14.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
16. 16.True or false: a tilt switch works only while pressed. (a) True (b) False
17. 17.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) when either is ON (c) never (d) when both are OFF
18. 18.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
19. 19.🔌 Is a keypad an input or an output for a microcontroller? (a) output (b) input
20. 20.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a toggle switch (c) a push button (d) a tilt switch
21. 21.⚙️ Which actuator would you use to show the temperature? (a) a motor (b) a display (c) an LED (d) a buzzer
22. 22.🧮 A 3.2 V battery is joined to 6 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
23. 23.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
24. 24.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
25. 25.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) it does not matter (d) both of them
26. 26.🔐 Is it a good or a risky habit to read app permissions? (a) risky habit (b) good habit
27. 27.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
28. 28.🔍 Which is the odd one out? (a) build with an adult near (b) dry your hands first (c) use small battery cells (d) touch a fallen wire
29. 29.🔌 Is a rubber band a conductor or an insulator? (a) an insulator (b) a conductor
30. 30.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) smaller (c) bigger (d) zero
31. 31.⚡ A device works on 9 V and takes 0.5 A. What is its power (in watts)? =
32. 32.🤖 Does a TV remote usually have a microcontroller inside? (a) No (b) Yes
33. 33.🔋 8 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
34. 34.🔌 Which part of a screwdriver should an electrician hold? (a) the bare end (b) the plastic handle (c) the metal tip (d) the steel shaft
35. 35.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = I ÷ V (d) P = V ÷ I
36. 36.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
37. 37.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
38. 38.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 100 (c) 10 (d) 60
39. 39.📏 How many amperes (A) is 2960 mA? =
40. 40.True or false: to use small battery cells is safe. (a) True (b) False

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