Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 702 · 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.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) switch the pump on/off (b) read the soil sensor (c) wait a few seconds
2. 2.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
   How many times does the LED blink in 2 seconds?
3. 3.🔁 count = 3
   while (count < 15) { count = count + 2 }
   How many times does the loop run?
4. 4.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) blinks 500 times (d) pauses for half a second
5. 5.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
6. 6.🔋 What is a battery? (a) a switch with a lid (b) two or more cells joined (c) a kind of bulb (d) one single wire
7. 7.🧩 A capacitor in a circuit can … (a) make light (b) measure heat (c) store charge briefly (d) spin a wheel
8. 8.🔺 A current of 25 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.🔐 Is it a good or a risky habit to read app permissions? (a) good habit (b) risky habit
10. 10.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a fuse or MCB (b) a long wire (c) a bulb (d) a plug top
11. 11.🔁 count = 9
    repeat 5 times { count = count + 3 }
    What is count at the end?
12. 12.🔺 A 7.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
13. 13.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
14. 14.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
15. 15.Which of these is the process? (a) the pump turns on (b) check if temp > 30 (c) an alert on the phone (d) a buzzer beeps
16. 16.🗺️ In an input → process → output plan, is “a motion sensor signal” the input, the process or the output? (a) output (b) process (c) input
17. 17.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) straight lines (c) little stars (d) dotted circles
18. 18.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) process (b) output (c) input
19. 19.🤖 What is a microcontroller? (a) a big desktop computer (b) a type of battery (c) a kind of bulb (d) a computer on one chip
20. 20.🌐 In an IoT system, which part measures the real world? (a) actuator (b) sensor (c) cloud server (d) microcontroller
21. 21.⏱️ A program says “wait 5500 ms”. How many seconds is that? =
22. 22.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 25 % (c) 50 % (d) 5 %
23. 23.🔦 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
24. 24.🌈 A resistor has the colour bands violet, black, orange. What is its value (in ohms)?
25. 25.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when both are OFF (c) when either is ON (d) when both are ON
26. 26.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) a bigger voltage (c) a smaller voltage (d) no voltage
27. 27.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 10 (d) 100
28. 28.🔁 total = 0
    for i = 1 to 3 { total = total + i }
    What is total at the end?
29. 29.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
30. 30.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
31. 31.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
32. 32.Which of these means the circuit is closed? (a) all wires are joined (b) the switch is OFF (c) a cell is taken out (d) a wire has come loose
33. 33.🧮 A 20 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
34. 34.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) neither line (c) both lines (d) the longer line
35. 35.⏱️ repeat 8 times { buzzer ON; wait 200 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
36. 36.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) each gets the full volts (c) a single current path (d) one bulb out, all go out
37. 37.True or false: on a cell, “the longer symbol line” means the + (positive) end. (a) False (b) True
38. 38.Which of these is not safe? (a) stop if a part gets hot (b) build with an adult near (c) take cells out after use (d) fly a kite near wires
39. 39.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) True (b) False
40. 40.🔍 Which is the odd one out? (a) a plastic ruler (b) a steel spoon (c) a graphite rod (d) a safety pin

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