Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 656 · 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: a slide switch stays where you flip it. (a) False (b) True
2. 2.🌈 In the resistor colour code, which number does green stand for?
3. 3.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “wait a few seconds”? (a) read the soil sensor (b) wait a few seconds
4. 4.🔐 Is it a good or a risky habit to cover unused cameras? (a) good habit (b) risky habit
5. 5.Which of these means the circuit is closed? (a) all wires are joined (b) a wire is cut (c) the switch is OFF (d) a cell is taken out
6. 6.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 8 HIGH
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
7. 7.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
8. 8.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined
9. 9.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the switch (c) the filament (d) the glass
10. 10.What does an LDR do? (a) boosts a small signal (b) limits the current (c) senses how bright it is (d) turns a fan or wheels
11. 11.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 30 °C. What happens? (a) fan ON (b) fan OFF
12. 12.🧾 A family uses 20 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
13. 13.True or false: a water heater mainly makes movement. (a) False (b) True
14. 14.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V + R (c) I = V ÷ R (d) I = V × R
15. 15.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
16. 16.🔋 A 3 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
17. 17.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 25) { show “Warm” } else { show “Cool” }
    The temperature is 22 °C. What is shown? (a) Cool (b) Warm (c) Hot
18. 18.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
19. 19.True or false: the voltmeter is joined across a part. (a) True (b) False
20. 20.💡 An LED is joined to a 3 V battery through a 220 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
21. 21.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “switch the pump on/off”? (a) read the soil sensor (b) switch the pump on/off
22. 22.Which of these has no microcontroller inside? (a) a digital thermometer (b) a smart watch (c) a candle (d) a TV remote
23. 23.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
24. 24.🧮 A 0.9 V battery is joined to 3 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
25. 25.🧭 Which part of a microcontroller board brings power and code? (a) the pins (b) the voltage regulator (c) the power LED (d) the USB port
26. 26.Which of these is an output? (a) a temperature sensor (b) a motion sensor (c) an LED (d) a push button
27. 27.True or false: to switch on lamps at dusk, use a soil moisture sensor. (a) False (b) True
28. 28.⚠️ Is it safe to touch a fallen wire? (a) not safe (b) safe
29. 29.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = I ÷ V (c) R = V ÷ I (d) R = V × I
30. 30.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the metal tip (c) the bare end (d) the plastic handle
31. 31.⚡ What does an electric toy car mainly change electricity into? (a) light (b) sound (c) heat (d) movement
32. 32.🔍 Which is the odd one out? (a) dry your hands first (b) fly kites in open fields (c) open a phone charger (d) take cells out after use
33. 33.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) an output (c) a fuse (d) a power source
34. 34.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 41 %. What happens? (a) pump OFF (b) pump ON
35. 35.Which of these is not safe? (a) fly kites in open fields (b) use small battery cells (c) build with an adult near (d) touch a switch when wet
36. 36.🔺 A current of 0.25 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.🧮 Resistors of 50 Ω and 330 Ω are joined in series. What is the total resistance (in ohms)?
38. 38.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
39. 39.🌐 In an IoT system, which part measures the real world? (a) Wi-Fi (b) cloud server (c) sensor (d) microcontroller
40. 40.🌈 In the resistor colour code, which number does violet stand for?

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