Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 966 · 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.💡 Why does an LED need a resistor in series? (a) to change its colour (b) to store charge (c) to make it brighter (d) to limit the current
2. 2.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) little stars (c) wavy lines (d) dotted circles
3. 3.🔘 Which kind of switch stays where you flip it? (a) a tilt switch (b) a slide switch (c) a toggle switch (d) a reed switch
4. 4.True or false: an iron nail is an insulator. (a) False (b) True
5. 5.⏱️ How many milliseconds is a wait of 2.3 seconds?
6. 6.🧮 Two equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
7. 7.🔁 count = 0
   repeat 3 times { count = count + 2 }
   What is count at the end?
8. 8.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) switch (b) cell (c) ammeter (d) LED
9. 9.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
10. 10.⚡ A device works on 24 V and takes 0.2 A. What is its power (in watts)? =
11. 11.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) switch off empty rooms (c) leave the TV on standby (d) close the fridge quickly
12. 12.⚡ A fan changes electrical energy mainly into which kind of energy? (a) chemical energy (b) light energy (c) sound energy (d) movement energy
13. 13.🔐 Is it a good or a risky habit to install software updates? (a) good habit (b) risky habit
14. 14.🔺 A current of 2.5 A flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
15. 15.Which of these is true of a parallel circuit? (a) many paths for current (b) a break stops every bulb (c) bulbs share the voltage (d) one bulb out, all go out
16. 16.Which of these mainly gives out heat? (a) a traffic signal (b) a table fan (c) a night lamp (d) an electric kettle
17. 17.Which job is done by the main chip? (a) brings power and code (b) shows the board is on (c) restarts the program (d) runs the program
18. 18.🔁 count = 1
    while (count < 9) { count = count + 4 }
    How many times does the loop run?
19. 19.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) one bulb out, all go out (c) a single current path (d) one out, the rest glow
20. 20.Which of these is a conductor? (a) a plastic straw (b) a wooden stick (c) a ceramic cup (d) a safety pin
21. 21.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber eraser across the gap. Does the bulb glow? (a) Yes (b) No
22. 22.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 0 % (d) 25 %
23. 23.True or false: a plastic straw is a conductor. (a) True (b) False
24. 24.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
25. 25.🔍 Which is the odd one out? (a) share only needed data (b) set up with a parent (c) set a strong password (d) ignore update messages
26. 26.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
27. 27.Which of these mainly makes sound? (a) a buzzer (b) an LED lamp (c) a traffic signal (d) a tube light
28. 28.Which job needs a motor? (a) open a gate to 90° (b) move water to plants (c) spin a robot’s wheels (d) turn to an exact angle
29. 29.🔁 What does a variable do in a program? (a) measures light (b) blinks an LED (c) joins two wires (d) stores a value
30. 30.Which of these is a good habit? (a) reuse one password (b) post your live location (c) accept every permission (d) set up with a parent
31. 31.True or false: a spinning top usually has a microcontroller inside. (a) True (b) False
32. 32.⏱️ How many milliseconds is a wait of 3.7 seconds?
33. 33.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
34. 34.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) large electric dial (d) low energy device
35. 35.⚙️ Which actuator would you use to spin a robot’s wheels? (a) an LED (b) a motor (c) a display (d) a buzzer
36. 36.🔍 Which sensor would you use to spot someone walking in? (a) a distance sensor (b) a sound sensor (c) a motion sensor (d) a temperature sensor
37. 37.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
38. 38.Which of these is a conductor? (a) a paper strip (b) a wooden stick (c) aluminium foil (d) a plastic ruler
39. 39.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
40. 40.🔺 A current of 1.5 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?

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