Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 97 · 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.🔺 A current of 0.25 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
2. 2.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
3. 3.🌈 A resistor has the colour bands white, violet, red. What is its value in kilo-ohms (kΩ)? =
4. 4.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
5. 5.🔺 A 6 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
6. 6.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) prints 1 (d) adds 1 to count
7. 7.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) read the soil sensor (b) wait a few seconds (c) switch the pump on/off (d) compare with the limit
8. 8.🔋 What is a battery? (a) a switch with a lid (b) two or more cells joined (c) one single wire (d) a kind of bulb
9. 9.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 100 (b) 1000 (c) 10 (d) 1024
10. 10.True or false: “HIGH or LOW only” is a digital signal. (a) False (b) True
11. 11.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
12. 12.🌈 In the resistor colour code, which number does red stand for?
13. 13.🔐 Which is the strongest password for a home smart camera? (a) password (b) admin (c) 123456 (d) Tiger#Lamp42!Moon
14. 14.Which of these is measured in amperes (A)? (a) resistance (b) current (c) how much a part resists (d) the push of a cell
15. 15.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V × I (c) P = V ÷ I (d) P = V + I
16. 16.🧭 Which part of a microcontroller board brings power and code? (a) the reset button (b) the USB port (c) the voltage regulator (d) the power LED
17. 17.True or false: a line lifted at a gap is the symbol for a switch. (a) False (b) True
18. 18.🔘 Which kind of switch flips up or down? (a) a push button (b) a reed switch (c) a slide switch (d) a toggle switch
19. 19.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the pins (b) the power LED (c) the main chip (d) the reset button
20. 20.🤖 Which is a safe power source for a beginner microcontroller board? (a) a wall socket directly (b) USB or a 9 V battery (c) bare mains wires (d) a 230 V cable
21. 21.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
22. 22.What does a buzzer do? (a) boosts a small signal (b) limits the current (c) glows using little power (d) makes a beeping sound
23. 23.📏 How many ohms (Ω) is 6.4 kΩ?
24. 24.Which of these is a conductor? (a) a plastic ruler (b) a dry cork (c) a ceramic cup (d) an iron nail
25. 25.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
26. 26.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) cell (b) battery (c) diode (d) LED
27. 27.Which of these has no microcontroller inside? (a) a smart watch (b) a toy robot (c) a hand pump (d) a microwave oven
28. 28.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
29. 29.⏱️ loop forever { LED ON; wait 500 ms; LED OFF; wait 300 ms }
    How many milliseconds does one blink (ON + OFF) take?
30. 30.🔢 To plan an electronics project, which comes first: “build it with an adult” or “draw the circuit diagram”? (a) build it with an adult (b) draw the circuit diagram
31. 31.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 400 ms }
    How many milliseconds does one blink (ON + OFF) take?
32. 32.Which of these wastes electricity? (a) use daylight to read (b) close the fridge quickly (c) iron one shirt at a time (d) unplug idle chargers
33. 33.True or false: a candle usually has a microcontroller inside. (a) False (b) True
34. 34.⚡ A device works on 12 V and takes 0.5 A. What is its power (in watts)? =
35. 35.🤖 Microcontroller or laptop: which one has no screen of its own? (a) microcontroller (b) laptop
36. 36.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) Yes (b) No
37. 37.🔍 Which is the odd one out? (a) a school bell (b) a doorbell (c) a traffic signal (d) a loudspeaker
38. 38.⚡ What does a street light mainly change electricity into? (a) movement (b) heat (c) light (d) sound
39. 39.True or false: “many paths for current” is true of a series circuit. (a) True (b) False
40. 40.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)

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