Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 963 · 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.🔺 A 4 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
2. 2.🤖 What is a microcontroller? (a) a kind of bulb (b) a computer on one chip (c) a type of battery (d) a big desktop computer
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.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) plastic is a conductor (c) plastic makes current (d) to make them heavy
5. 5.Which of these has no microcontroller inside? (a) a TV remote (b) a smart watch (c) a digital thermometer (d) a spinning top
6. 6.🧩 Which component smooths a wobbly supply? (a) thermistor (b) capacitor (c) fuse (d) LDR
7. 7.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets bigger (c) becomes zero (d) gets smaller
8. 8.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) wavy lines (c) dotted circles (d) straight lines
9. 9.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop
10. 10.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) output (b) process (c) input
11. 11.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 5 seconds?
12. 12.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
13. 13.💡 5 identical bulbs are in parallel and each bulb has its own switch on its path. 2 of the switches are OFF and the rest are ON. How many bulbs glow?
14. 14.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
15. 15.What does an LDR do? (a) boosts a small signal (b) senses how bright it is (c) turns a fan or wheels (d) senses how hot it is
16. 16.True or false: a circle with M inside is the symbol for an LED. (a) False (b) True
17. 17.💡 What does LED stand for? (a) low energy device (b) light energy dial (c) large electric dial (d) light-emitting diode
18. 18.🔋 How many volts does one ordinary torch cell give? (a) 0.5 V (b) 1.5 V (c) 230 V (d) 15 V
19. 19.⚠️ Is it safe to poke things in a socket? (a) not safe (b) safe
20. 20.True or false: energy used each second is measured in watts (W). (a) True (b) False
21. 21.💡 3 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
22. 22.True or false: to fly kites in open fields is safe. (a) True (b) False
23. 23.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 13 °C. What is shown? (a) Warm (b) Cool (c) Hot
24. 24.🔁 Is the circuit closed or open if a cell is taken out? (a) closed (b) open
25. 25.True or false: a traffic signal mainly gives out heat. (a) True (b) False
26. 26.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the length of a wire (d) the colour of light
27. 27.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) the widest gap (d) any band
28. 28.True or false: “a light level reading” is the input. (a) False (b) True
29. 29.🔐 Who should decide which smart devices go in a child’s room? (a) nobody at all (b) an online stranger (c) the app’s adverts (d) a parent or guardian
30. 30.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
31. 31.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
32. 32.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
33. 33.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) the else part (d) both parts
34. 34.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) a wire is cut (d) the loop is complete
35. 35.🌈 A resistor has the colour bands blue, black, brown. What is its value (in ohms)?
36. 36.🧭 Which part of a microcontroller board brings power and code? (a) the power LED (b) the USB port (c) the voltage regulator (d) the pins
37. 37.True or false: if all wires are joined, the circuit is closed and current flows. (a) True (b) False
38. 38.Which of these usually has a microcontroller inside? (a) a bicycle bell (b) a digital alarm clock (c) a candle (d) a wind-up toy
39. 39.Which of these uses electricity? (a) a bicycle dynamo (b) a television (c) a power station (d) a solar panel
40. 40.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)

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