Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 868 · 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.True or false: a toggle switch stays where you flip it. (a) False (b) True
2. 2.🔢 To plan an electronics project, which comes first: “list inputs and outputs” or “pick a problem to solve”? (a) pick a problem to solve (b) list inputs and outputs
3. 3.📏 Which unit measures voltage? (a) ohm (Ω) (b) watt (W) (c) ampere (A) (d) volt (V)
4. 4.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
5. 5.Which job needs a light sensor? (a) stop a robot near walls (b) keep an incubator warm (c) switch on lamps at dusk (d) switch on with a clap
6. 6.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) voltmeter (b) resistor (c) wire (d) cell
7. 7.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
8. 8.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = I ÷ V (d) R = V × I
9. 9.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) wait a few seconds (b) compare with the limit (c) switch the pump on/off (d) read the soil sensor
10. 10.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 200 ms }
    How many times does the LED blink in 1 second?
11. 11.💡 6 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 1 and 2 are taken out of their holders. How many bulbs glow?
12. 12.🔌 Is a rubber band a conductor or an insulator? (a) an insulator (b) a conductor
13. 13.True or false: a laptop runs one small program. (a) False (b) True
14. 14.Which job is done by the main chip? (a) restarts the program (b) keeps the voltage steady (c) runs the program (d) brings power and code
15. 15.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 2 seconds?
16. 16.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
17. 17.True or false: a wooden stick is an insulator. (a) True (b) False
18. 18.⚙️ Which actuator would you use to beep an alarm? (a) an LED (b) a buzzer (c) a servo motor (d) a motor
19. 19.🌈 In the resistor colour code, which number does violet stand for?
20. 20.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) the widest gap (c) any band (d) the gold band
21. 21.📏 How many kilo-ohms (kΩ) is 1800 Ω? =
22. 22.What does an LDR do? (a) has coloured bands (b) senses how bright it is (c) is a resistance knob (d) blows if current is high
23. 23.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the else part (b) the if part (c) neither part (d) both parts
24. 24.🔘 Which kind of switch closes near a magnet? (a) a tilt switch (b) a push button (c) a slide switch (d) a reed switch
25. 25.True or false: a doorbell mainly makes movement. (a) False (b) True
26. 26.🌐 In an IoT system, which part carries the data? (a) Wi-Fi (b) cloud server (c) sensor (d) actuator
27. 27.True or false: to tap unknown app links is a good habit. (a) False (b) True
28. 28.⏱️ repeat 5 times { buzzer ON; wait 900 ms; buzzer OFF; wait 1000 ms }
    How many milliseconds does this take in all?
29. 29.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) less than either one (c) their sum (d) always zero
30. 30.🔌 Which metal is used for most electric wires at home? (a) rubber (b) glass (c) copper (d) plastic
31. 31.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I × R (d) V = I + R
32. 32.🔺 A current of 0.25 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
33. 33.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) stay the same (d) bigger
34. 34.🌈 In the resistor colour code, which number does grey stand for?
35. 35.True or false: a wooden stick is a conductor. (a) False (b) True
36. 36.🔍 Which is the odd one out? (a) a light sensor (b) a buzzer (c) a water pump (d) a servo motor
37. 37.What does a fuse do? (a) lets current go one way (b) limits the current (c) blows if current is high (d) has coloured bands
38. 38.True or false: a circle with V inside is the symbol for a voltmeter. (a) False (b) True
39. 39.🧮 A 20 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
40. 40.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False

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