Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 851 · 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: to open a phone charger is safe. (a) True (b) False
2. 2.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
3. 3.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a plastic gap (d) a broken path
4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 79000 Ω resistor? (a) violet-white-yellow (b) violet-white-red (c) violet-white-orange (d) white-violet-orange
5. 5.Which of these is safe? (a) dry your hands first (b) throw cells in a fire (c) use a cable with cuts (d) poke things in a socket
6. 6.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) energy used each second (d) the length of a wire
7. 7.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I × R (c) V = I + R (d) V = I ÷ R
8. 8.🔋 What is a battery? (a) a kind of bulb (b) one single wire (c) a switch with a lid (d) two or more cells joined
9. 9.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
10. 10.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 250 ms }
    How many milliseconds does one blink (ON + OFF) take?
11. 11.What does a slide switch do? (a) works only while pressed (b) closes near a magnet (c) springs back when let go (d) slides side to side
12. 12.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
13. 13.🔁 count = 2
    while (count < 34) { count = count + 4 }
    How many times does the loop run?
14. 14.🔍 Which sensor would you use to measure classroom noise? (a) a sound sensor (b) a rain sensor (c) a light sensor (d) a temperature sensor
15. 15.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 52 Ω resistor? (a) blue-red-black (b) green-red-black (c) green-red-brown (d) red-green-black
16. 16.⚠️ Is it safe to touch a switch when wet? (a) not safe (b) safe
17. 17.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
18. 18.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) No (b) Yes
19. 19.🔋 Cells joined + to − in a row (series) give … (a) a smaller voltage (b) no voltage (c) a bigger voltage (d) the same voltage
20. 20.🔦 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
21. 21.True or false: on a cell, “usually the black wire” means the + (positive) end. (a) False (b) True
22. 22.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 180 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
23. 23.🗺️ Before building a project, what should you write down first? (a) nothing at all (b) inputs and outputs (c) the final price (d) the box colour
24. 24.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V + I (d) P = V × I
25. 25.🔘 Which kind of switch springs back when let go? (a) a push button (b) a tilt switch (c) a reed switch (d) a slide switch
26. 26.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) switch the pump on/off (b) wait a few seconds (c) read the soil sensor (d) compare with the limit
27. 27.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
28. 28.🔘 Which kind of switch works only while pressed? (a) a push button (b) a tilt switch (c) a reed switch (d) a toggle switch
29. 29.Which of these gives us electricity? (a) a refrigerator (b) a computer (c) a generator (d) a television
30. 30.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
31. 31.📏 How many ohms (Ω) is 9.5 kΩ?
32. 32.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 4 minutes?
33. 33.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an oil lamp (c) a filament bulb (d) an LED lamp
34. 34.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) False (b) True
35. 35.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
36. 36.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
37. 37.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
38. 38.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) own switch for each bulb (c) a single current path (d) one bulb out, all go out
39. 39.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 510 Ω resistor? (a) green-brown-brown (b) green-brown-red (c) brown-green-brown (d) green-brown-black
40. 40.📏 Which unit measures the flow of charge? (a) watt (W) (b) ohm (Ω) (c) ampere (A) (d) volt (V)

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