Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 141 · 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 of these is an input? (a) a temperature sensor (b) an LED (c) a servo motor (d) a speaker
2. 2.🧩 Which component blows if current is high? (a) thermistor (b) fuse (c) diode (d) buzzer
3. 3.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) quick and clear for all (d) symbols are heavier
4. 4.📏 How many kilowatts (kW) is 1250 W? =
5. 5.🔺 A 12 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
6. 6.🤖 Microcontroller or laptop: which one needs much more power? (a) microcontroller (b) laptop
7. 7.🌐 Is a paper calendar an IoT device? (a) an IoT device (b) not an IoT device
8. 8.🔺 A current of 25 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
9. 9.True or false: to close a window in rain, use a gas sensor. (a) False (b) True
10. 10.🔺 A current of 1.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
11. 11.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
12. 12.True or false: a tube light mainly gives out light. (a) False (b) True
13. 13.True or false: how much a part resists is measured in amperes (A). (a) True (b) False
14. 14.🔋 What should you do with used-up cells? (a) cut them open (b) bury them in soil (c) give them for recycling (d) throw them in a fire
15. 15.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a small battery pack (c) a wall socket (d) a mains extension board
16. 16.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
17. 17.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the output (c) the process (d) the battery
18. 18.True or false: a torch mainly gives out light. (a) False (b) True
19. 19.🔦 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 metal paper clip. Does the bulb glow? (a) No (b) Yes
20. 20.Which of these is an output? (a) a light sensor (b) a turning knob (c) a temperature sensor (d) a water pump
21. 21.🔁 count = 3
    repeat 7 times { count = count + 7 }
    What is count at the end?
22. 22.True or false: “many values in a range” is an analog signal. (a) False (b) True
23. 23.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a rubber eraser across the gap. Does the bulb glow? (a) Yes (b) No
24. 24.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 61. What happens? (a) green LED ON (b) red LED ON
25. 25.✏️ In a circuit diagram, which part is drawn as a straight line? (a) junction (b) wire (c) battery (d) voltmeter
26. 26.🔘 Which kind of switch flips up or down? (a) a toggle switch (b) a slide switch (c) a reed switch (d) a push button
27. 27.🔁 x = 1
    repeat 2 times { x = x × 2 }
    What is x at the end?
28. 28.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
29. 29.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 5 seconds?
30. 30.Which job needs an LED? (a) move water to plants (b) turn to an exact angle (c) show a status light (d) beep an alarm
31. 31.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) wire (b) motor (c) battery (d) ammeter
32. 32.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the widest gap (d) the one nearest an end
33. 33.Which of these is the input? (a) a buzzer beeps (b) the fan starts (c) a button press (d) decide if soil is dry
34. 34.💡 Why does an LED need a resistor in series? (a) to change its colour (b) to store charge (c) to make it brighter (d) to limit the current
35. 35.⚙️ Which actuator would you use to beep an alarm? (a) a pump (b) a buzzer (c) a motor (d) an LED
36. 36.Which of these means the circuit is open? (a) the switch is ON (b) all wires are joined (c) the bulb is unscrewed (d) the loop is complete
37. 37.🔍 A distance sensor sends a sound pulse and hears the echo 9 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
38. 38.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
39. 39.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
40. 40.Which of these is not safe? (a) use mains for a project (b) stop if a part gets hot (c) keep drinks far away (d) dry your hands first

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