Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 144 · 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.🧮 Resistors of 68 Ω, 330 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
2. 2.🔍 Which sensor would you use to start a fan when hot? (a) a distance sensor (b) a temperature sensor (c) a light sensor (d) a sound sensor
3. 3.True or false: a microcontroller has no screen of its own. (a) False (b) True
4. 4.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) battery (b) wire (c) ammeter (d) capacitor
5. 5.🔍 Which is the odd one out? (a) use LED lamps (b) run fans in empty rooms (c) set the AC to 24 °C (d) close the fridge quickly
6. 6.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 460 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
7. 7.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 41 Ω resistor? (a) yellow-brown-black (b) yellow-brown-brown (c) green-brown-black (d) brown-yellow-black
8. 8.Which of these mainly makes sound? (a) an electric kettle (b) a buzzer (c) a night lamp (d) a water heater
9. 9.🔁 What does a variable do in a program? (a) measures light (b) blinks an LED (c) stores a value (d) joins two wires
10. 10.🔺 A current of 50 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
11. 11.True or false: a plain rectangle is the symbol for a cell. (a) False (b) True
12. 12.🔺 A current of 40 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
13. 13.Which of these uses electricity? (a) a power station (b) a washing machine (c) a cell (d) a bicycle dynamo
14. 14.🌈 In the resistor colour code, which number does white stand for?
15. 15.🔢 To plan an electronics project, what comes right after “draw the circuit diagram”? (a) build it with an adult (b) test it and fix it (c) list inputs and outputs (d) pick a problem to solve
16. 16.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a slide switch (c) a tilt switch (d) a push button
17. 17.🔘 Which kind of switch works only while pressed? (a) a slide switch (b) a push button (c) a reed switch (d) a toggle switch
18. 18.⚠️ Is it safe to stop if a part gets hot? (a) safe (b) not safe
19. 19.🧮 A 50 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
20. 20.🏠 Which is a smart-home example? (a) a printed map (b) a hand fan (c) a candle in a jar (d) lights on from an app
21. 21.🤖 How does a new program get onto a microcontroller board? (a) typed on the chip (b) uploaded over USB (c) drawn with a pen (d) sent by sound
22. 22.🔋 How many 1.2 V cells must be joined in series to give 3.6 V?
23. 23.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
24. 24.Which drawing is the symbol for a motor? (a) a long and a short line (b) a circle with a cross (c) a circle with M inside (d) a dot where wires meet
25. 25.🌐 In an IoT system, which part carries the data? (a) phone app (b) microcontroller (c) sensor (d) Wi-Fi
26. 26.🔢 To get a sensor reading onto a phone, which comes first: “the sensor measures” or “the cloud stores it”? (a) the cloud stores it (b) the sensor measures
27. 27.🌐 How does a home IoT device usually send its data to the app? (a) by post (b) by shouting (c) through a candle (d) over Wi-Fi
28. 28.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) series (b) parallel
29. 29.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) it does not matter (c) only one (d) both of them
30. 30.True or false: to share camera links is a risky habit. (a) True (b) False
31. 31.🔐 Is it a good or a risky habit to share only needed data? (a) good habit (b) risky habit
32. 32.🧩 Which component limits the current? (a) LED (b) buzzer (c) diode (d) resistor
33. 33.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
34. 34.Which of these is the input? (a) an LED lights up (b) an alert on the phone (c) a temperature reading (d) compare with a limit
35. 35.🔐 Who should decide which smart devices go in a child’s room? (a) nobody at all (b) the app’s adverts (c) a parent or guardian (d) an online stranger
36. 36.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = R ÷ V (c) I = V × R (d) I = V ÷ R
37. 37.🧩 Which component makes things spin? (a) fuse (b) motor (c) potentiometer (d) thermistor
38. 38.🔍 Which is the odd one out? (a) read app permissions (b) change default passwords (c) share camera links (d) share only needed data
39. 39.🤖 Which is a safe power source for a beginner microcontroller board? (a) a 230 V cable (b) USB or a 9 V battery (c) a wall socket directly (d) bare mains wires
40. 40.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True

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