Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 896 · 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.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) OFF (b) ON
2. 2.🔋 2 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
3. 3.What does a tilt switch do? (a) closes when tipped over (b) closes near a magnet (c) springs back when let go (d) flips up or down
4. 4.🔺 A current of 50 mA flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
5. 5.True or false: to change default passwords is a risky habit. (a) False (b) True
6. 6.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 5 % (d) 25 %
7. 7.What does a transistor do? (a) senses how hot it is (b) smooths a wobbly supply (c) boosts a small signal (d) senses how bright it is
8. 8.🧾 A 500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
9. 9.🔍 A distance sensor sends a sound pulse and hears the echo 8 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
10. 10.💡 Why is house wiring done in parallel? (a) to save copper only (b) so all go off together (c) each gets full voltage (d) to make bulbs dim
11. 11.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the size of a cell (d) the colour of light
12. 12.🧩 Which component senses how hot it is? (a) potentiometer (b) buzzer (c) resistor (d) thermistor
13. 13.💡 5 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. Bulb 1 is taken out of its holder. How many bulbs glow?
14. 14.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
15. 15.🌈 In the resistor colour code, which number does brown stand for?
16. 16.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) light energy (b) sound energy (c) movement energy (d) chemical energy
17. 17.🧮 A 47 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
18. 18.⚡ What does an electric toy car mainly change electricity into? (a) light (b) heat (c) sound (d) movement
19. 19.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
20. 20.True or false: the voltmeter measures voltage. (a) True (b) False
21. 21.🔺 A current of 2.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
22. 22.True or false: a smart watch has no microcontroller inside. (a) True (b) False
23. 23.Which of these is true of a parallel circuit? (a) a single current path (b) a break stops every bulb (c) each gets the full volts (d) bulbs share the voltage
24. 24.⚙️ Which actuator would you use to move water to plants? (a) a servo motor (b) a pump (c) a motor (d) a buzzer
25. 25.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
26. 26.🗺️ In an input → process → output plan, is “a button press” the input, the process or the output? (a) output (b) process (c) input
27. 27.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 16 seconds?
28. 28.📏 In the water-pipe picture of a circuit, current is like … (a) a narrow pipe (b) the flow of water (c) the pipe colour (d) the water pressure
29. 29.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
30. 30.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) capacitor (b) diode (c) battery (d) ammeter
31. 31.🔁 repeat 5 times { repeat 6 times { beep } }
    How many beeps are there?
32. 32.🔋 Does a generator give electricity or use electricity? (a) uses electricity (b) gives electricity
33. 33.True or false: a slide switch closes when tipped over. (a) False (b) True
34. 34.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
35. 35.🔋 A 6 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
36. 36.Which of these is an IoT device? (a) a plain wall switch (b) a plain table fan (c) a Wi-Fi doorbell camera (d) a wind-up clock
37. 37.Which of these is the input? (a) an alert on the phone (b) a soil moisture reading (c) decide if soil is dry (d) compare with a limit
38. 38.🧩 Which component turns a fan or wheels? (a) LDR (b) LED (c) motor (d) resistor
39. 39.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
40. 40.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the else part (c) the if part (d) neither part

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