Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 260 · 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.⚡ Power tells us … (a) the length of a wire (b) energy used each second (c) the size of a cell (d) the colour of light
2. 2.True or false: to throw cells in a fire is safe. (a) True (b) False
3. 3.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = I ÷ R (d) V = R ÷ I
4. 4.🔋 8 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
5. 5.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V + I (c) P = V × I (d) P = V ÷ I
6. 6.🔺 A current of 10 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
7. 7.⏱️ How many milliseconds is a wait of 3.5 seconds?
8. 8.🤖 Does a microwave oven usually have a microcontroller inside? (a) Yes (b) No
9. 9.True or false: a buzzer mainly makes movement. (a) False (b) True
10. 10.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
11. 11.True or false: “compare with a limit” is the output. (a) True (b) False
12. 12.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) input (b) output
13. 13.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
14. 14.🔺 A current of 0.25 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🌐 Is a wind-up clock an IoT device? (a) an IoT device (b) not an IoT device
16. 16.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) input (b) process (c) output
17. 17.🔍 Which is the odd one out? (a) accept every permission (b) keep factory passwords (c) tap unknown app links (d) cover unused cameras
18. 18.Which of these is a conductor? (a) a paper strip (b) a ceramic cup (c) a glass marble (d) a steel coin
19. 19.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap
20. 20.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 350 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
21. 21.True or false: to use a cable with cuts is safe. (a) False (b) True
22. 22.🔁 count = 0
    while (count < 15) { count = count + 3 }
    How many times does the loop run?
23. 23.🔁 count = 1
    repeat 2 times { count = count + 9 }
    What is count at the end?
24. 24.🔺 A current of 2.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🔍 An object is 136 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
26. 26.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a paper strip across the gap. Does the bulb glow? (a) No (b) Yes
27. 27.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a safety pin across the gap. Does the bulb glow? (a) No (b) Yes
28. 28.Which drawing is the symbol for a junction? (a) a long and a short line (b) a dot where wires meet (c) a small empty box (d) a circle with a cross
29. 29.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) False (b) True
30. 30.Which job is done by the USB port? (a) brings power and code (b) keeps the voltage steady (c) connect sensors and LEDs (d) runs the program
31. 31.🔺 A 1 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
32. 32.True or false: a spinning top usually has a microcontroller inside. (a) True (b) False
33. 33.⚙️ Which actuator would you use to move water to plants? (a) an LED (b) a display (c) a buzzer (d) a pump
34. 34.🔘 Which kind of switch works only while pressed? (a) a slide switch (b) a reed switch (c) a tilt switch (d) a push button
35. 35.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
36. 36.🔺 A current of 0.25 A flows when 0.75 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.Which job needs an LED? (a) open a gate to 90° (b) show a status light (c) move water to plants (d) show the temperature
38. 38.🌐 In an IoT system, which part shows data to you? (a) sensor (b) phone app (c) actuator (d) microcontroller
39. 39.🤖 Which is a safe power source for a beginner microcontroller board? (a) a wall socket directly (b) bare mains wires (c) a 230 V cable (d) USB or a 9 V battery
40. 40.Which of these has no microcontroller inside? (a) a digital alarm clock (b) a smart watch (c) a plain wall switch (d) a TV remote

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