Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 915 · 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.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
2. 2.Which of these mainly gives out light? (a) a rice cooker (b) an electric iron (c) an LED lamp (d) a table fan
3. 3.⚙️ Which actuator would you use to show a status light? (a) a servo motor (b) a motor (c) an LED (d) a buzzer
4. 4.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) each gets full voltage (c) so all go off together (d) to save copper only
5. 5.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) the colour of light (d) energy used each second
6. 6.True or false: “a door: open or shut” is an analog signal. (a) True (b) False
7. 7.🤖 Where does the board keep its program when the power is off? (a) the resistor (b) the USB cable (c) the power LED (d) flash memory
8. 8.💡 2 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
9. 9.🔢 To get a sensor reading onto a phone, what comes right after “the board reads it”? (a) it is sent by Wi-Fi (b) the cloud stores it (c) the app shows it (d) the sensor measures
10. 10.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
11. 11.True or false: a potentiometer has coloured bands. (a) False (b) True
12. 12.🔘 Which kind of switch works only while pressed? (a) a push button (b) a tilt switch (c) a reed switch (d) a toggle switch
13. 13.🔍 Which is the odd one out? (a) take cells out after use (b) throw cells in a fire (c) touch a fallen wire (d) use a cable with cuts
14. 14.💡 In a series circuit, how many paths does the current have? (a) two (b) one for each bulb (c) one (d) none
15. 15.Which of these is a conductor? (a) a rubber band (b) a paper strip (c) a woollen thread (d) a steel coin
16. 16.True or false: a TV remote usually has a microcontroller inside. (a) True (b) False
17. 17.True or false: a wind-up toy has no microcontroller inside. (a) True (b) False
18. 18.💡 A red LED uses 2 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
19. 19.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
20. 20.🔋 Does a bicycle dynamo give electricity or use electricity? (a) uses electricity (b) gives electricity
21. 21.🔍 Which is the odd one out? (a) an iron nail (b) a copper wire (c) a graphite rod (d) a rubber band
22. 22.What does a capacitor do? (a) beeps for an alarm (b) stores a little charge (c) makes things spin (d) has coloured bands
23. 23.🔺 A 1 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
24. 24.🧩 Which part changes electrical energy into movement? (a) an LED (b) a resistor (c) a motor (d) a fuse
25. 25.Which of these is a risky habit? (a) log out of shared phones (b) post your live location (c) install software updates (d) turn off unused gadgets
26. 26.Which of these mainly gives out light? (a) a loudspeaker (b) a mixer grinder (c) a torch (d) a siren
27. 27.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) switch the pump on/off (b) compare with the limit (c) wait a few seconds (d) read the soil sensor
28. 28.Which of these is a risky habit? (a) change default passwords (b) install software updates (c) accept every permission (d) set a strong password
29. 29.🔺 A 2 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
30. 30.🔁 Is the circuit closed or open if the switch is ON? (a) closed (b) open
31. 31.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “read the soil sensor”? (a) compare with the limit (b) read the soil sensor
32. 32.Which of these is the output? (a) a motion sensor signal (b) the pump turns on (c) a light level reading (d) a temperature reading
33. 33.🌈 In the resistor colour code, which number does blue stand for?
34. 34.⏱️ repeat 2 times { buzzer ON; wait 800 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
35. 35.🌈 A resistor has the colour bands green, grey, yellow. What is its value in kilo-ohms (kΩ)? =
36. 36.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) the same voltage (c) no voltage (d) a smaller voltage
37. 37.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
38. 38.Which of these is an input? (a) a water pump (b) an LED (c) a turning knob (d) a motor
39. 39.True or false: a laptop needs much more power. (a) True (b) False
40. 40.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) to make it colourful (c) quick and clear for all (d) symbols are heavier

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