Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 428 · 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.📏 In the water-pipe picture of a circuit, resistance is like … (a) a bigger tank (b) the water pressure (c) the flow of water (d) a narrow pipe
2. 2.🧮 Resistors of 470 Ω, 50 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
3. 3.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
4. 4.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the battery (c) the process (d) the output
5. 5.🌈 Which band is read first on a resistor? (a) the gold band (b) any band (c) the one nearest an end (d) the widest gap
6. 6.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) through a candle (c) by post (d) over Wi-Fi
7. 7.True or false: to keep factory passwords is a risky habit. (a) False (b) True
8. 8.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) bulbs share the voltage (c) one bulb out, all go out (d) one out, the rest glow
9. 9.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = R ÷ I (c) V = I + R (d) V = I ÷ R
10. 10.💡 In a series circuit, how many paths does the current have? (a) one (b) none (c) two (d) one for each bulb
11. 11.💡 An LED is joined to a 6 V battery through a 1000 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) lights up (c) may burn out
12. 12.🔺 A 30 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
13. 13.⚡ What does a room heater mainly change electricity into? (a) heat (b) light (c) movement (d) sound
14. 14.🔘 Which kind of switch flips up or down? (a) a toggle switch (b) a reed switch (c) a push button (d) a slide switch
15. 15.📏 Which unit measures the push of a cell? (a) ampere (A) (b) ohm (Ω) (c) volt (V) (d) watt (W)
16. 16.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
17. 17.🔍 Which is the odd one out? (a) a light sensor (b) an LED (c) a motor (d) a water pump
18. 18.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
19. 19.Which of these is true of a series circuit? (a) many paths for current (b) one bulb out, all go out (c) used in house wiring (d) own switch for each bulb
20. 20.Which of these wastes electricity? (a) run fans in empty rooms (b) switch off empty rooms (c) use LED lamps (d) use daylight to read
21. 21.What does a reed switch do? (a) flips up or down (b) slides side to side (c) closes near a magnet (d) works only while pressed
22. 22.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
23. 23.🧮 A 4 V battery is joined to 8 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
24. 24.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) False (b) True
25. 25.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) True (b) False
26. 26.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 29000 Ω resistor? (a) white-red-orange (b) red-white-yellow (c) red-white-orange (d) red-white-red
27. 27.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) stores current (c) changes the voltage (d) makes electricity
28. 28.💡 Why is house wiring done in parallel? (a) so all go off together (b) to save copper only (c) each gets full voltage (d) to make bulbs dim
29. 29.🧮 A 20 Ω resistor is joined in series with two equal 50 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
30. 30.True or false: “a button: pressed or not” is an analog signal. (a) True (b) False
31. 31.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
32. 32.💡 2 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. Bulbs 1 and 2 are taken out of their holders. How many bulbs glow?
33. 33.True or false: a brass key is an insulator. (a) False (b) True
34. 34.Which of these is true of a parallel circuit? (a) each gets the full volts (b) one bulb out, all go out (c) bulbs share the voltage (d) a single current path
35. 35.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
36. 36.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 5 % (c) 0 % (d) 50 %
37. 37.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) used in house wiring (c) a single current path (d) one bulb out, all go out
38. 38.⚙️ Which actuator would you use to move water to plants? (a) an LED (b) a display (c) a pump (d) a servo motor
39. 39.🔌 Is a keypad an input or an output for a microcontroller? (a) input (b) output
40. 40.⚡ Which tiny particles drift along a metal wire to carry the current? (a) dust particles (b) electrons (c) water drops (d) photons

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