Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 157 · 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.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) waits 500 seconds (d) blinks 500 times
2. 2.Which of these is the input? (a) check if temp > 30 (b) a light level reading (c) the pump turns on (d) count button presses
3. 3.📏 Which unit measures resistance? (a) volt (V) (b) watt (W) (c) ampere (A) (d) ohm (Ω)
4. 4.True or false: an electric iron mainly makes sound. (a) False (b) True
5. 5.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
6. 6.⏱️ How many milliseconds is a wait of 3.5 seconds?
7. 7.🧩 Which component limits the current? (a) motor (b) capacitor (c) potentiometer (d) resistor
8. 8.Which job needs a display? (a) spin a robot’s wheels (b) beep an alarm (c) show the temperature (d) move water to plants
9. 9.True or false: a dot where wires meet is the symbol for a junction. (a) False (b) True
10. 10.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “list inputs and outputs”? (a) list inputs and outputs (b) pick a problem to solve
11. 11.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a buzzer (d) a resistor
12. 12.🌈 Which band is read first on a resistor? (a) any band (b) the widest gap (c) the gold band (d) the one nearest an end
13. 13.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
14. 14.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
15. 15.⚡ A device works on 12 V and takes 0.1 A. What is its power (in watts)? =
16. 16.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) the else part (d) neither part
17. 17.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
18. 18.🔍 Which is the odd one out? (a) climb an electric pole (b) take cells out after use (c) throw cells in a fire (d) open a phone charger
19. 19.🔍 Which is the odd one out? (a) an electric kettle (b) an electric drill (c) a water heater (d) a rice cooker
20. 20.🔐 Privacy for a smart device means controlling … (a) its colour (b) its battery size (c) who can see your data (d) how loud it beeps
21. 21.⚡ Power tells us … (a) the size of a cell (b) the length of a wire (c) energy used each second (d) the colour of light
22. 22.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a toggle switch (c) a slide switch (d) a push button
23. 23.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “wait a few seconds”? (a) wait a few seconds (b) compare with the limit
24. 24.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 5 hours?
25. 25.⚡ A device works on 5 V and takes 0.1 A. What is its power (in watts)? =
26. 26.Which of these is an IoT device? (a) an app-controlled bulb (b) a plain table fan (c) a wind-up clock (d) a paper calendar
27. 27.⚠️ Who should be with you when you build a circuit? (a) nobody (b) a trusted adult (c) a stranger online (d) a younger child
28. 28.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is ON and B is ON. Does the bulb glow? (a) Yes (b) No
29. 29.What does a toggle switch do? (a) works only while pressed (b) closes when tipped over (c) stays where you flip it (d) closes near a magnet
30. 30.True or false: “a tilt switch: on or off” is an analog signal. (a) True (b) False
31. 31.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 160 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
32. 32.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) stays the same (d) becomes zero
33. 33.💡 A battery lights 5 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
34. 34.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) quick and clear for all (d) to hide the circuit
35. 35.🌈 A resistor has the colour bands green, green, red. What is its value in kilo-ohms (kΩ)? =
36. 36.🤖 Does a digital alarm clock usually have a microcontroller inside? (a) Yes (b) No
37. 37.🔍 A distance sensor sends a sound pulse and hears the echo 4 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
38. 38.🌈 A resistor has the colour bands yellow, red, red. What is its value (in ohms)?
39. 39.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
40. 40.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a plastic ruler. Does the bulb glow? (a) No (b) Yes

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