Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 808 · 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 drawing is the symbol for a motor? (a) triangle, bar and arrows (b) a circle with M inside (c) a plain rectangle (d) two or more cell symbols
2. 2.🔍 Which is the odd one out? (a) a soil moisture reading (b) a button press (c) a light level reading (d) compare with a limit
3. 3.True or false: “the fan starts” is the process. (a) False (b) True
4. 4.🗺️ Before building a project, what should you write down first? (a) the box colour (b) the final price (c) nothing at all (d) inputs and outputs
5. 5.🌈 In the resistor colour code, which number does red stand for?
6. 6.Which job is done by the reset button? (a) brings power and code (b) keeps the voltage steady (c) restarts the program (d) shows the board is on
7. 7.Which of these is true of a parallel circuit? (a) used in house wiring (b) one bulb out, all go out (c) a single current path (d) a break stops every bulb
8. 8.⏱️ repeat 4 times { buzzer ON; wait 500 ms; buzzer OFF; wait 300 ms }
   How many milliseconds does this take in all?
9. 9.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
10. 10.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
11. 11.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
12. 12.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
13. 13.Which of these wastes electricity? (a) use LED lamps (b) iron one shirt at a time (c) close the fridge quickly (d) switch off empty rooms
14. 14.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 68. What happens? (a) red LED ON (b) green LED ON
15. 15.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
16. 16.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
17. 17.True or false: the ammeter is joined across a part. (a) False (b) True
18. 18.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 6 V supply. What current flows (in mA)?
19. 19.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 9 minutes?
20. 20.True or false: to close the fridge quickly saves electricity. (a) False (b) True
21. 21.🤖 How does a new program get onto a microcontroller board? (a) sent by sound (b) typed on the chip (c) uploaded over USB (d) drawn with a pen
22. 22.🧮 A 4.5 V battery is joined to 10 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
23. 23.True or false: the ammeter measures voltage. (a) False (b) True
24. 24.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
25. 25.📏 How many kilo-ohms (kΩ) is 8000 Ω? =
26. 26.📶 Digital or analog: a button: pressed or not? (a) analog (b) digital
27. 27.🧮 Four equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
28. 28.🔺 A current of 0.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
29. 29.🔍 An object is 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
30. 30.⚡ A 4.5 W device works on 9 V. What current does it take (in amperes)? =
31. 31.🔍 Which sensor would you use to switch on lamps at dusk? (a) a motion sensor (b) a light sensor (c) a temperature sensor (d) a distance sensor
32. 32.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) by post (c) through a candle (d) over Wi-Fi
33. 33.🔐 Is it a good or a risky habit to log out of shared phones? (a) risky habit (b) good habit
34. 34.📏 Which unit measures current? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)
35. 35.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the battery (b) the input (c) the output (d) the process
36. 36.True or false: a slide switch slides side to side. (a) True (b) False
37. 37.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) pauses for half a second (c) turns the LED off (d) blinks 500 times
38. 38.Which of these is an output? (a) a keypad (b) a servo motor (c) a turning knob (d) a push button
39. 39.📏 How many milliamperes (mA) make 1 ampere? (a) 1000 (b) 10 (c) 60 (d) 100
40. 40.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed

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