Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 886 · 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.🔘 Which kind of switch flips up or down? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a push button
2. 2.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) True (b) False
3. 3.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) turns the LED off (c) waits 500 seconds (d) pauses for half a second
4. 4.⚠️ Is it safe to stop if a part gets hot? (a) not safe (b) safe
5. 5.🌈 A resistor has the colour bands brown, green, yellow. What is its value in kilo-ohms (kΩ)? =
6. 6.🤖 if (light < 200) { lamp ON } else { lamp OFF }
   The light sensor reads 114. What happens? (a) lamp ON (b) lamp OFF
7. 7.🌐 Each reading a sensor sends is 10 bytes. How many bytes do 50 readings take?
8. 8.🏠 Which is a smart-home example? (a) a candle in a jar (b) a hand fan (c) a printed map (d) lights on from an app
9. 9.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 300 ms }
   How many milliseconds does one blink (ON + OFF) take?
10. 10.🔺 A current of 25 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
11. 11.⏱️ A program says “wait 7000 ms”. How many seconds is that? =
12. 12.⚙️ What is an actuator? (a) an output that acts (b) a sensor (c) a battery (d) a program
13. 13.What does a fuse do? (a) makes things spin (b) is a resistance knob (c) blows if current is high (d) limits the current
14. 14.🔺 A current of 25 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
15. 15.True or false: if the switch is ON, the circuit is open and no current flows. (a) False (b) True
16. 16.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
17. 17.Which job needs an LED? (a) spin a robot’s wheels (b) open a gate to 90° (c) beep an alarm (d) show a status light
18. 18.🔋 A 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
19. 19.🔍 Which is the odd one out? (a) the fan starts (b) an LED lights up (c) a buzzer beeps (d) compare with a limit
20. 20.🧩 A capacitor in a circuit can … (a) measure heat (b) store charge briefly (c) make light (d) spin a wheel
21. 21.⚡ Which tiny particles drift along a metal wire to carry the current? (a) photons (b) dust particles (c) electrons (d) water drops
22. 22.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 133. What happens? (a) lamp ON (b) lamp OFF
23. 23.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
24. 24.🧮 A 47 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
25. 25.Which of these is safe? (a) open a phone charger (b) fly a kite near wires (c) stop if a part gets hot (d) throw cells in a fire
26. 26.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) battery (b) voltmeter (c) cell (d) switch
27. 27.True or false: “an alert on the phone” is the output. (a) True (b) False
28. 28.Which of these gives us electricity? (a) a mobile phone (b) a refrigerator (c) a solar panel (d) a computer
29. 29.True or false: if all wires are joined, the circuit is open and no current flows. (a) True (b) False
30. 30.True or false: if a cell is taken out, the circuit is open and no current flows. (a) False (b) True
31. 31.🔐 Privacy for a smart device means controlling … (a) its colour (b) how loud it beeps (c) its battery size (d) who can see your data
32. 32.True or false: a candle has no microcontroller inside. (a) True (b) False
33. 33.🔁 repeat 2 times { repeat 4 times { beep } }
    How many beeps are there?
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) Yes (b) No
35. 35.🔋 3 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
36. 36.🔺 A current of 0.25 A flows when 1.25 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.📏 Which unit measures the flow of charge? (a) volt (V) (b) ohm (Ω) (c) watt (W) (d) ampere (A)
38. 38.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) nuclear energy (c) electrical energy (d) wind energy
39. 39.🔘 Which kind of switch slides side to side? (a) a push button (b) a tilt switch (c) a toggle switch (d) a slide switch
40. 40.💡 What does LED stand for? (a) low energy device (b) large electric dial (c) light energy dial (d) light-emitting diode

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