Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 681 · 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.True or false: a reed switch slides side to side. (a) True (b) False
2. 2.🔍 Which is the odd one out? (a) build with an adult near (b) use mains for a project (c) touch a switch when wet (d) use a cable with cuts
3. 3.🔁 x = 5
   repeat 5 times { x = x × 2 }
   What is x at the end?
4. 4.🔌 Why are electric wires covered in plastic? (a) to make them heavy (b) plastic makes current (c) plastic is a conductor (d) plastic is an insulator
5. 5.🔺 A current of 0.1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
6. 6.Which of these mainly makes movement? (a) a tube light (b) an electric drill (c) a night lamp (d) an electric iron
7. 7.Which of these is the input? (a) decide if soil is dry (b) a motion sensor signal (c) an LED lights up (d) the fan starts
8. 8.Which of these is an input? (a) a small display (b) a buzzer (c) a keypad (d) a motor
9. 9.🔌 Which metal is used for most electric wires at home? (a) glass (b) plastic (c) copper (d) rubber
10. 10.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
11. 11.What does a potentiometer do? (a) turns a fan or wheels (b) makes a beeping sound (c) is a resistance knob (d) makes things spin
12. 12.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the length of a wire (d) the colour of light
13. 13.Which of these is measured in volts (V)? (a) resistance (b) how much a part resists (c) the flow of charge (d) voltage
14. 14.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
15. 15.What does a capacitor do? (a) lets current go one way (b) glows using little power (c) stores a little charge (d) makes a beeping sound
16. 16.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
17. 17.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
18. 18.True or false: a tube light mainly gives out heat. (a) True (b) False
19. 19.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
20. 20.💡 6 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?
21. 21.⏱️ A program says “wait 4500 ms”. How many seconds is that? =
22. 22.🔋 Does a battery give electricity or use electricity? (a) uses electricity (b) gives electricity
23. 23.🧭 Which part of a microcontroller board runs the program? (a) the voltage regulator (b) the main chip (c) the pins (d) the USB port
24. 24.🧮 Resistors of 22 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
25. 25.Which of these is a good habit? (a) share camera links (b) keep factory passwords (c) reuse one password (d) install software updates
26. 26.🤖 “if (A AND B)” is true when … (a) only A is true (b) both are false (c) only B is true (d) both A and B are true
27. 27.💡 5 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 5 glow? (a) No (b) Yes
28. 28.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) symbols are heavier (d) quick and clear for all
29. 29.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 490 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
30. 30.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) bigger (d) stay the same
31. 31.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) an input (c) an output (d) a power source
32. 32.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🔍 Which is the odd one out? (a) a steel spoon (b) a plastic straw (c) a plastic ruler (d) a ceramic cup
34. 34.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) read the soil sensor (b) wait a few seconds (c) switch the pump on/off
35. 35.🗺️ Before building a project, what should you write down first? (a) inputs and outputs (b) the box colour (c) nothing at all (d) the final price
36. 36.🔺 A 3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
37. 37.🔌 Is a rubber eraser a conductor or an insulator? (a) an insulator (b) a conductor
38. 38.🤖 if (light < 300) { lamp ON } else { lamp OFF }
    The light sensor reads 266. What happens? (a) lamp OFF (b) lamp ON
39. 39.🌈 In the resistor colour code, which number does black stand for?
40. 40.Which of these wastes electricity? (a) use LED lamps (b) leave the TV on standby (c) unplug idle chargers (d) switch off empty rooms

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