Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 574 · 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 a buzzer do? (a) senses how bright it is (b) beeps for an alarm (c) blows if current is high (d) has coloured bands
2. 2.🗺️ In an input → process → output plan, is “a button press” the input, the process or the output? (a) input (b) output (c) process
3. 3.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
4. 4.🔺 A current of 0.1 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
5. 5.True or false: “a tilt switch: on or off” is an analog signal. (a) True (b) False
6. 6.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) spin a wheel (d) measure heat
7. 7.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) True (b) False
8. 8.⚡ What does a ceiling fan mainly change electricity into? (a) heat (b) light (c) sound (d) movement
9. 9.🔺 A current of 2.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
10. 10.🔍 Which sensor would you use to stop a robot near walls? (a) a soil moisture sensor (b) a distance sensor (c) a temperature sensor (d) a gas sensor
11. 11.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I + R (c) V = R ÷ I (d) V = I × R
12. 12.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) type it all in (c) share it with friends (d) ask a parent first
13. 13.Which of these is safe? (a) stop if a part gets hot (b) use mains for a project (c) open a phone charger (d) fly a kite near wires
14. 14.💡 In a series circuit, how many paths does the current have? (a) one (b) none (c) two (d) one for each bulb
15. 15.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) bulb (b) wire (c) capacitor (d) ammeter
16. 16.True or false: “a motion sensor signal” is the output. (a) True (b) False
17. 17.True or false: to use LED lamps saves electricity. (a) False (b) True
18. 18.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) False (b) True
19. 19.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) a candle (c) an oil lamp (d) an LED lamp
20. 20.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
21. 21.💡 3 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
22. 22.🔋 6 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
23. 23.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
24. 24.⚙️ Which actuator would you use to move water to plants? (a) a pump (b) a motor (c) an LED (d) a buzzer
25. 25.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
26. 26.🤖 Microcontroller or laptop: which one has no screen of its own? (a) microcontroller (b) laptop
27. 27.📶 Digital or analog: how loud a sound is? (a) analog (b) digital
28. 28.🔁 count = 1
    repeat 9 times { count = count + 7 }
    What is count at the end?
29. 29.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
30. 30.Which of these is an insulator? (a) a woollen thread (b) an iron nail (c) a steel coin (d) a metal paper clip
31. 31.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 10 (d) 100
32. 32.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 13 cm. What happens? (a) buzzer beeps (b) buzzer is silent
33. 33.🔍 Which is the odd one out? (a) a battery torch (b) a Wi-Fi doorbell camera (c) a plain wall switch (d) a plain table fan
34. 34.True or false: to use mains for a project is not safe. (a) False (b) True
35. 35.🧮 A 22 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
36. 36.🔁 What does a variable do in a program? (a) measures light (b) joins two wires (c) stores a value (d) blinks an LED
37. 37.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = V × I (c) R = V ÷ I (d) R = I ÷ V
38. 38.True or false: a capacitor smooths a wobbly supply. (a) False (b) True
39. 39.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
40. 40.⚠️ Is it safe to open a phone charger? (a) safe (b) not safe

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