Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 402 · 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 “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) neither part (d) the if part
2. 2.🧩 Which component senses how hot it is? (a) LED (b) LDR (c) motor (d) thermistor
3. 3.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger
4. 4.Which of these mainly gives out heat? (a) an LED lamp (b) a water heater (c) an electric toy car (d) a table fan
5. 5.⚠️ Is it safe to stay away from pylons? (a) not safe (b) safe
6. 6.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) output (b) input (c) process
7. 7.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
8. 8.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
9. 9.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the USB port (b) the voltage regulator (c) the pins (d) the power LED
10. 10.🔦 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 paper strip. Does the bulb glow? (a) No (b) Yes
11. 11.What does a reed switch do? (a) slides side to side (b) flips up or down (c) closes near a magnet (d) stays where you flip it
12. 12.🧾 A family uses 130 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
13. 13.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
14. 14.🌈 A resistor has the colour bands brown, black, yellow. What is its value in kilo-ohms (kΩ)? =
15. 15.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 1 hour?
16. 16.🔺 A current of 10 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.Which of these gives us electricity? (a) an air conditioner (b) a television (c) a cell (d) a computer
18. 18.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) cell (b) LED (c) resistor (d) battery
19. 19.🔍 Which is the odd one out? (a) a water pump (b) a push button (c) a motion sensor (d) a temperature sensor
20. 20.🔁 repeat 2 times { repeat 5 times { beep } }
    How many beeps are there?
21. 21.🔁 repeat 4 times { repeat 5 times { beep } }
    How many beeps are there?
22. 22.🔋 5 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
23. 23.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel coin across the gap. Does the bulb glow? (a) No (b) Yes
24. 24.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
25. 25.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to limit the current (d) to change its colour
26. 26.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 volt (d) 1 kilowatt-hour (kWh)
27. 27.🌈 A resistor has the colour bands red, white, black. What is its value (in ohms)?
28. 28.Which of these is the process? (a) decide if soil is dry (b) a soil moisture reading (c) a button press (d) the pump turns on
29. 29.True or false: to stop if a part gets hot is safe. (a) False (b) True
30. 30.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) any band (d) the widest gap
31. 31.True or false: to use mains for a project is safe. (a) True (b) False
32. 32.🔘 Which kind of switch stays where you flip it? (a) a tilt switch (b) a slide switch (c) a push button (d) a toggle switch
33. 33.🔍 Which is the odd one out? (a) a buzzer (b) a loudspeaker (c) a school bell (d) an electric kettle
34. 34.⏱️ repeat 10 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
35. 35.True or false: energy used each second is measured in watts (W). (a) True (b) False
36. 36.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
37. 37.🔺 A current of 40 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
38. 38.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
39. 39.Which of these is a good habit? (a) reuse one password (b) keep factory passwords (c) share camera links (d) turn off unused gadgets
40. 40.🌐 How does a home IoT device usually send its data to the app? (a) through a candle (b) by post (c) by shouting (d) over Wi-Fi

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