Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 540 · 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 IoT stand for? (a) Input of Tools (b) Internet of Things (c) Internet of Talk (d) Inside of Toys
2. 2.Which of these is measured in volts (V)? (a) the flow of charge (b) current (c) resistance (d) the push of a cell
3. 3.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
4. 4.⚡ What does a traffic signal mainly change electricity into? (a) movement (b) sound (c) heat (d) light
5. 5.Which of these is the output? (a) check if temp > 30 (b) the fan starts (c) a button press (d) count button presses
6. 6.🤖 Where does the board keep its program when the power is off? (a) flash memory (b) the power LED (c) the USB cable (d) the resistor
7. 7.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = V ÷ R (d) I = R ÷ V
8. 8.🔁 count = 3
   repeat 2 times { count = count + 6 }
   What is count at the end?
9. 9.✏️ In a cell symbol, which line is the + terminal? (a) the shorter line (b) the longer line (c) both lines (d) neither line
10. 10.⚡ A 0.5 W device works on 5 V. What current does it take (in amperes)? =
11. 11.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 780 Ω resistor? (a) violet-grey-black (b) violet-grey-brown (c) grey-violet-brown (d) violet-grey-red
12. 12.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 25 %. What happens? (a) pump ON (b) pump OFF
13. 13.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
14. 14.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) symbols are heavier (c) to hide the circuit (d) quick and clear for all
15. 15.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 350 ms }
    How many milliseconds does one blink (ON + OFF) take?
16. 16.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
17. 17.🧩 Which component makes a beeping sound? (a) motor (b) resistor (c) buzzer (d) LDR
18. 18.🔺 A current of 20 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
19. 19.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 20 °C. What is shown? (a) Hot (b) Warm (c) Cool
20. 20.🔋 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)? =
21. 21.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) many paths for current (c) bulbs share the voltage (d) a break stops every bulb
22. 22.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they get dimmer (d) they explode
23. 23.Which of these is a risky habit? (a) post your live location (b) change default passwords (c) read app permissions (d) set a strong password
24. 24.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) to make them heavy (c) plastic is an insulator (d) plastic is a conductor
25. 25.💡 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
26. 26.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) smaller (d) stay the same
27. 27.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
28. 28.💡 3 identical bulbs are joined in series with a 4.5 V battery (ideal wires). How many volts does each bulb get? =
29. 29.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) the switch is ON (c) a wire is cut (d) a wire has come loose
30. 30.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 25 % (c) 5 % (d) 50 %
31. 31.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 9 V (c) 1.5 V (d) 12 V
32. 32.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
33. 33.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
34. 34.True or false: “how bright a room is” is an analog signal. (a) True (b) False
35. 35.🔘 Which kind of switch slides side to side? (a) a toggle switch (b) a slide switch (c) a tilt switch (d) a reed switch
36. 36.🔺 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
37. 37.🔺 A current of 10 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
39. 39.Which drawing is the symbol for a cell? (a) a dot where wires meet (b) a long and a short line (c) two equal parallel lines (d) a straight line
40. 40.True or false: to install software updates is a risky habit. (a) True (b) False

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