Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 746 · 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 0.5 A. What is its power (in watts)?
2. 2.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = I ÷ V (d) P = V ÷ I
3. 3.True or false: an iron nail is an insulator. (a) False (b) True
4. 4.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
5. 5.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the USB port (b) the power LED (c) the voltage regulator (d) the main chip
6. 6.🔺 A 0.4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
7. 7.Which of these is true of a series circuit? (a) many paths for current (b) one out, the rest glow (c) a single current path (d) own switch for each bulb
8. 8.🌈 A resistor has the colour bands brown, grey, orange. What is its value (in ohms)?
9. 9.📏 How many kilo-ohms (kΩ) is 2400 Ω? =
10. 10.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) False (b) True
11. 11.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 kilowatt-hour (kWh) (c) 1 ampere (d) 1 watt
12. 12.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1024 (b) 10 (c) 1000 (d) 100
13. 13.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 390 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
14. 14.🔘 When a switch is ON, the circuit is … (a) broken (b) cut (c) open (d) closed
15. 15.Which of these mainly makes sound? (a) a table fan (b) an electric drill (c) a room heater (d) a loudspeaker
16. 16.🔺 A current of 10 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
17. 17.🔺 A 25 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
18. 18.True or false: a line lifted at a gap is the symbol for a switch. (a) False (b) True
19. 19.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) a motor (d) an LED
20. 20.🔌 Is a plastic straw a conductor or an insulator? (a) a conductor (b) an insulator
21. 21.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.Which of these usually has a microcontroller inside? (a) a wind-up toy (b) a hand pump (c) a spinning top (d) a washing machine
23. 23.Which of these is an output? (a) an LED (b) a light sensor (c) a push button (d) a motion sensor
24. 24.🔁 What does “count = count + 1” do? (a) takes 1 away (b) prints 1 (c) adds 1 to count (d) sets count to 1
25. 25.🔍 Which is the odd one out? (a) the pump turns on (b) decide if soil is dry (c) check if temp > 30 (d) compare with a limit
26. 26.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel
27. 27.🔺 A current of 50 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🔢 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 sensor measures (c) the cloud stores it (d) the app shows it
29. 29.🔐 Is it a good or a risky habit to tap unknown app links? (a) good habit (b) risky habit
30. 30.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
31. 31.What does a thermistor do? (a) boosts a small signal (b) senses how bright it is (c) stores a little charge (d) senses how hot it is
32. 32.🌈 In the resistor colour code, which number does violet stand for?
33. 33.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
34. 34.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) blinks 500 times (c) waits 500 seconds (d) turns the LED off
35. 35.🌈 A resistor has the colour bands brown, violet, black. What is its value (in ohms)?
36. 36.🔍 Which is the odd one out? (a) throw cells in a fire (b) touch a switch when wet (c) fly kites in open fields (d) fly a kite near wires
37. 37.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they keep glowing (c) they all go out (d) they get dimmer
38. 38.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) bulb (b) resistor (c) junction (d) capacitor
39. 39.🧮 A 68 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
40. 40.Which job is done by the reset button? (a) restarts the program (b) keeps the voltage steady (c) connect sensors and LEDs (d) runs the program

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