Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 474 · 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.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
2. 2.True or false: a straight line is the symbol for a battery. (a) True (b) False
3. 3.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the length of a wire (d) the colour of light
4. 4.🔁 count = 3
   repeat 4 times { count = count + 4 }
   What is count at the end?
5. 5.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
6. 6.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
7. 7.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
8. 8.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “the board reads it”? (a) the board reads it (b) the sensor measures
9. 9.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
10. 10.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 4 hours?
11. 11.Which of these wastes electricity? (a) use old filament bulbs (b) switch off empty rooms (c) use daylight to read (d) use LED lamps
12. 12.📏 Voltmeter or ammeter: which one is joined in series? (a) ammeter (b) voltmeter
13. 13.🧮 A 0.6 V battery is joined to 3 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
14. 14.🔍 Which is the odd one out? (a) use mains for a project (b) use a cable with cuts (c) stay away from pylons (d) poke things in a socket
15. 15.🔐 Is it a good or a risky habit to post your live location? (a) good habit (b) risky habit
16. 16.Which of these means the circuit is closed? (a) the switch is ON (b) a wire has come loose (c) a wire is cut (d) the bulb is unscrewed
17. 17.🔺 A 4.7 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
18. 18.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
19. 19.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) read the soil sensor (b) switch the pump on/off (c) wait a few seconds (d) compare with the limit
20. 20.✏️ In a circuit diagram, which part is drawn as a circle with M inside? (a) diode (b) motor (c) resistor (d) voltmeter
21. 21.📏 Which unit measures voltage? (a) ampere (A) (b) watt (W) (c) ohm (Ω) (d) volt (V)
22. 22.🌈 In the resistor colour code, which number does brown stand for?
23. 23.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = V × R (d) I = R ÷ V
24. 24.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) turns the LED off (c) waits 500 seconds (d) blinks 500 times
25. 25.🔺 A current of 25 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🔁 x = 4
    repeat 3 times { x = x × 2 }
    What is x at the end?
27. 27.🔍 Which is the odd one out? (a) ignore update messages (b) keep factory passwords (c) share only needed data (d) accept every permission
28. 28.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
29. 29.🔺 A current of 2.5 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
30. 30.True or false: a plain wall switch usually has a microcontroller inside. (a) False (b) True
31. 31.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) No (b) Yes
32. 32.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) Yes (b) No
33. 33.Which of these is measured in ohms (Ω)? (a) energy used each second (b) resistance (c) the push of a cell (d) voltage
34. 34.🧾 A 1500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
35. 35.🌈 In the resistor colour code, which number does orange stand for?
36. 36.Which of these is safe? (a) touch a switch when wet (b) throw cells in a fire (c) use small battery cells (d) poke things in a socket
37. 37.💡 In a series circuit, how many paths does the current have? (a) two (b) none (c) one (d) one for each bulb
38. 38.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I × R (c) V = R ÷ I (d) V = I + R
39. 39.Which of these is a conductor? (a) a paper strip (b) aluminium foil (c) a woollen thread (d) a rubber band
40. 40.🔋 Does a power station give electricity or use electricity? (a) uses electricity (b) gives electricity

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