Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 42 · 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 is the odd one out? (a) a loudspeaker (b) a mixer grinder (c) an electric toy car (d) a ceiling fan
2. 2.🌐 In an IoT system, which part carries the data? (a) microcontroller (b) sensor (c) Wi-Fi (d) cloud server
3. 3.True or false: to make a parking alarm, use a temperature sensor. (a) True (b) False
4. 4.Which of these is true of a parallel circuit? (a) bulbs share the voltage (b) a single current path (c) one out, the rest glow (d) one bulb out, all go out
5. 5.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a resistor (d) a capacitor
6. 6.🤖 if (moisture < 40) { pump ON } else { pump OFF }
   The soil moisture sensor reads 27 %. What happens? (a) pump ON (b) pump OFF
7. 7.Which job needs a pump? (a) spin a robot’s wheels (b) move water to plants (c) beep an alarm (d) show a status light
8. 8.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 300 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
9. 9.🔘 Which kind of switch works only while pressed? (a) a tilt switch (b) a reed switch (c) a push button (d) a toggle switch
10. 10.🌈 In the resistor colour code, which number does violet stand for?
11. 11.Which of these means the circuit is closed? (a) the switch is ON (b) the switch is OFF (c) a cell is taken out (d) a wire has come loose
12. 12.📏 How many ohms (Ω) is 9.5 kΩ?
13. 13.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🔢 To plan an electronics project, what comes right after “build it with an adult”? (a) list inputs and outputs (b) test it and fix it (c) pick a problem to solve (d) draw the circuit diagram
15. 15.True or false: to reuse one password is a good habit. (a) True (b) False
16. 16.True or false: a rubber band is a conductor. (a) True (b) False
17. 17.True or false: “a door: open or shut” is a digital signal. (a) True (b) False
18. 18.🌈 A resistor has the colour bands grey, red, yellow. What is its value in kilo-ohms (kΩ)? =
19. 19.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) Yes (b) No
20. 20.True or false: a circle with M inside is the symbol for a motor. (a) True (b) False
21. 21.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 1 hour?
22. 22.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) No (b) Yes
23. 23.🔁 x = 4
    repeat 2 times { x = x × 2 }
    What is x at the end?
24. 24.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
25. 25.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 480 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
26. 26.💡 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?
27. 27.🔺 A current of 25 mA flows when 5.5 V is joined across a resistor. What is its resistance (in ohms)?
28. 28.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) False (b) True
29. 29.🔐 Is it a good or a risky habit to log out of shared phones? (a) risky habit (b) good habit
30. 30.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 67000 Ω resistor? (a) violet-blue-orange (b) blue-violet-yellow (c) blue-violet-orange (d) blue-violet-red
31. 31.🧮 Resistors of 22 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?
32. 32.🌈 A resistor has the colour bands red, yellow, brown. What is its value (in ohms)?
33. 33.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) a candle (d) an oil lamp
34. 34.True or false: to close a window in rain, use a rain sensor. (a) True (b) False
35. 35.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) switch the pump on/off (b) wait a few seconds (c) compare with the limit
36. 36.🔍 Which is the odd one out? (a) a small display (b) a motor (c) a water pump (d) a turning knob
37. 37.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
38. 38.💡 An LED is joined to a 6 V battery through a 470 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) lights up (c) does not light
39. 39.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
40. 40.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I × R (c) V = I + R (d) V = R ÷ I

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