Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 669 · 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.🌐 Is a plain wall switch an IoT device? (a) an IoT device (b) not an IoT device
2. 2.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
3. 3.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) False (b) True
4. 4.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
   The temperature is 13 °C. What is shown? (a) Hot (b) Warm (c) Cool
5. 5.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. How many bulbs glow?
6. 6.📏 How many amperes (A) is 1440 mA? =
7. 7.🔺 A 6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
8. 8.True or false: the voltmeter is joined in series. (a) False (b) True
9. 9.🔋 A 3 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
10. 10.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) True (b) False
11. 11.💡 What does LED stand for? (a) light energy dial (b) low energy device (c) large electric dial (d) light-emitting diode
12. 12.🔺 A current of 0.1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
13. 13.Which of these is safe? (a) climb an electric pole (b) use small battery cells (c) touch a switch when wet (d) fly a kite near wires
14. 14.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
15. 15.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
16. 16.🔍 Which is the odd one out? (a) touch a switch when wet (b) touch a fallen wire (c) dry your hands first (d) poke things in a socket
17. 17.⏱️ repeat 8 times { buzzer ON; wait 600 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
18. 18.Which of these gives us electricity? (a) a television (b) a refrigerator (c) a water pump (d) a battery
19. 19.🔘 Which kind of switch flips up or down? (a) a push button (b) a tilt switch (c) a reed switch (d) a toggle switch
20. 20.Which of these is safe? (a) open a phone charger (b) touch a switch when wet (c) fly a kite near wires (d) build with an adult near
21. 21.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) ammeter (b) capacitor (c) bulb (d) voltmeter
22. 22.True or false: the voltmeter measures voltage. (a) False (b) True
23. 23.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
24. 24.🔐 Is it a good or a risky habit to keep factory passwords? (a) good habit (b) risky habit
25. 25.True or false: to switch on with a clap, use a temperature sensor. (a) False (b) True
26. 26.🌈 A resistor has the colour bands violet, violet, red. What is its value in kilo-ohms (kΩ)? =
27. 27.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
28. 28.Which of these wastes electricity? (a) use daylight to read (b) unplug idle chargers (c) switch off empty rooms (d) run fans in empty rooms
29. 29.🔋 3 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
30. 30.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) any band (c) the widest gap (d) the gold band
31. 31.True or false: one tall, one short bar is the symbol for a bulb. (a) True (b) False
32. 32.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) nuclear energy (c) electrical energy (d) wind energy
33. 33.⚡ What does a rice cooker mainly change electricity into? (a) movement (b) sound (c) light (d) heat
34. 34.What does the sensor do? (a) acts on a command (b) carries the data (c) measures the real world (d) stores data online
35. 35.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
36. 36.🔋 A 3 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
37. 37.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 35 °C. What happens? (a) fan ON (b) fan OFF
38. 38.📏 Which unit measures power? (a) volt (V) (b) ohm (Ω) (c) watt (W) (d) ampere (A)
39. 39.🔺 A current of 2 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
40. 40.True or false: a push button springs back when let go. (a) True (b) False

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