Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 270 · 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.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
2. 2.🔍 Which is the odd one out? (a) check if temp > 30 (b) a button press (c) count button presses (d) compare with a limit
3. 3.True or false: “one out, the rest glow” is true of a series circuit. (a) False (b) True
4. 4.⚠️ Why must we never touch switches with wet hands? (a) it spoils the paint (b) water makes it cold (c) it is just untidy (d) water carries current
5. 5.🔍 Which is the odd one out? (a) a water pump (b) a temperature sensor (c) a push button (d) a sound sensor
6. 6.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
7. 7.🔢 To plan an electronics project, what comes right after “list inputs and outputs”? (a) pick a problem to solve (b) build it with an adult (c) draw the circuit diagram (d) test it and fix it
8. 8.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) True (b) False
9. 9.💡 4 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
10. 10.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) cell (b) switch (c) LED (d) bulb
11. 11.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) iron one shirt at a time (d) close the fridge quickly
12. 12.🧩 Which component smooths a wobbly supply? (a) diode (b) fuse (c) capacitor (d) resistor
13. 13.🔺 A current of 0.2 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
14. 14.⚡ 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
15. 15.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
16. 16.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) output (b) input (c) process
17. 17.True or false: a microcontroller needs much more power. (a) False (b) True
18. 18.🔋 What should you do with used-up cells? (a) throw them in a fire (b) bury them in soil (c) cut them open (d) give them for recycling
19. 19.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
20. 20.🔁 count = 2
    while (count < 12) { count = count + 2 }
    How many times does the loop run?
21. 21.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) wait a few seconds (b) compare with the limit (c) switch the pump on/off
22. 22.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an oil lamp (d) an LED lamp
23. 23.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
24. 24.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the switch (c) the base (d) the filament
25. 25.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = V × I (d) P = I ÷ V
26. 26.🔋 A 6 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
27. 27.🔘 Which kind of switch closes near a magnet? (a) a toggle switch (b) a slide switch (c) a tilt switch (d) a reed switch
28. 28.🔍 Which is the odd one out? (a) use mains for a project (b) use small battery cells (c) climb an electric pole (d) throw cells in a fire
29. 29.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
30. 30.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
31. 31.🔍 Which is the odd one out? (a) decide if soil is dry (b) a motion sensor signal (c) a soil moisture reading (d) a button press
32. 32.💡 What happens if an LED is put in backwards? (a) it changes colour (b) it does not light (c) it makes a sound (d) it lights brighter
33. 33.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) motor (b) cell (c) bulb (d) wire
34. 34.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
35. 35.🔌 Is a glass marble a conductor or an insulator? (a) a conductor (b) an insulator
36. 36.True or false: a washing machine has no microcontroller inside. (a) False (b) True
37. 37.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 5 % (c) 50 % (d) 25 %
38. 38.🔍 Which is the odd one out? (a) fly kites in open fields (b) poke things in a socket (c) stop if a part gets hot (d) keep drinks far away
39. 39.🌈 A resistor has the colour bands brown, yellow, red. What is its value (in ohms)?
40. 40.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?

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