Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 387 · 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.🔁 What do we call a circuit with a break in it? (a) a full circuit (b) a closed circuit (c) a series circuit (d) an open circuit
2. 2.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
3. 3.Which of these mainly makes sound? (a) a ceiling fan (b) a street light (c) a doorbell (d) a table fan
4. 4.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the output (c) the battery (d) the process
5. 5.🔺 A current of 20 mA flows when 6.6 V is joined across a resistor. What is its resistance (in ohms)?
6. 6.🧩 Which component stores a little charge? (a) LED (b) motor (c) capacitor (d) transistor
7. 7.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to change its colour (d) to limit the current
8. 8.🔍 Which is the odd one out? (a) touch a switch when wet (b) use mains for a project (c) dry your hands first (d) use a cable with cuts
9. 9.🔺 A current of 20 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
10. 10.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) compare with the limit (b) wait a few seconds (c) read the soil sensor
11. 11.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 0 % (c) 25 % (d) 50 %
12. 12.🔺 A current of 3 A flows when 36 V is joined across a resistor. What is its resistance (in ohms)?
13. 13.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
14. 14.True or false: the ammeter measures voltage. (a) False (b) True
15. 15.🔍 Which is the odd one out? (a) keep factory passwords (b) accept every permission (c) log out of shared phones (d) post your live location
16. 16.True or false: to stay away from pylons is safe. (a) True (b) False
17. 17.🌈 In the resistor colour code, which number does violet stand for?
18. 18.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
19. 19.🔺 A current of 20 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
20. 20.🌐 In an IoT system, which part reads values, decides? (a) phone app (b) Wi-Fi (c) sensor (d) microcontroller
21. 21.Which of these mainly gives out light? (a) a rice cooker (b) an electric toy car (c) a street light (d) a table fan
22. 22.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) switch (b) ammeter (c) cell (d) junction
23. 23.Which of these is a conductor? (a) a rubber eraser (b) a wooden stick (c) an iron nail (d) a glass marble
24. 24.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) iron one shirt at a time (d) close the fridge quickly
25. 25.Which of these is not safe? (a) dry your hands first (b) build with an adult near (c) use small battery cells (d) climb an electric pole
26. 26.📏 Which unit measures resistance? (a) ohm (Ω) (b) ampere (A) (c) volt (V) (d) watt (W)
27. 27.🔍 Which is the odd one out? (a) a battery torch (b) a fitness band with app (c) a paper calendar (d) a plain wall switch
28. 28.Which of these gives us electricity? (a) an air conditioner (b) a wind turbine (c) a television (d) a refrigerator
29. 29.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
30. 30.⏱️ loop forever { LED ON; wait 550 ms; LED OFF; wait 600 ms }
    How many milliseconds does one blink (ON + OFF) take?
31. 31.🔌 Which part of a screwdriver should an electrician hold? (a) the metal tip (b) the steel shaft (c) the bare end (d) the plastic handle
32. 32.⚡ What does a tube light mainly change electricity into? (a) sound (b) movement (c) light (d) heat
33. 33.⚡ A solar panel changes which kind of energy into electricity? (a) sound energy (b) chemical energy (c) wind energy (d) light energy
34. 34.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) by Wi-Fi (c) in series (d) not joined
35. 35.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) both lines (c) neither line (d) the longer line
36. 36.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) ammeter (b) bulb (c) cell (d) LED
37. 37.⚡ What does an electric toy car mainly change electricity into? (a) light (b) sound (c) movement (d) heat
38. 38.⚙️ What is an actuator? (a) a battery (b) a program (c) a sensor (d) an output that acts
39. 39.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
40. 40.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) let strangers use it (b) tell it your passwords (c) put it in the bathroom (d) mute it when not in use

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