Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 879 · 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.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
2. 2.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
   The distance sensor reads 15 cm. What happens? (a) buzzer beeps (b) buzzer is silent
3. 3.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pull them by the hand (b) pour water on them (c) wait and watch (d) shout for an adult
4. 4.🌈 A resistor has the colour bands grey, violet, red. What is its value (in ohms)?
5. 5.Which of these is not safe? (a) touch a fallen wire (b) stay away from pylons (c) build with an adult near (d) fly kites in open fields
6. 6.True or false: to open a phone charger is safe. (a) True (b) False
7. 7.🔢 To run one loop of a plant-watering program, which is the FIRST step? (a) switch the pump on/off (b) read the soil sensor (c) wait a few seconds (d) compare with the limit
8. 8.📏 How many amperes (A) is 960 mA? =
9. 9.📏 In the water-pipe picture of a circuit, voltage is like … (a) the tap handle (b) the water pressure (c) the water tank lid (d) the pipe colour
10. 10.✏️ In a circuit diagram, which part is drawn as a circle with M inside? (a) wire (b) switch (c) junction (d) motor
11. 11.🌈 A resistor has the colour bands red, brown, black. What is its value (in ohms)?
12. 12.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) a candle (d) an LED lamp
13. 13.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) little stars (c) dotted circles (d) wavy lines
14. 14.🔺 A current of 1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
15. 15.Which job needs a pump? (a) turn to an exact angle (b) spin a robot’s wheels (c) move water to plants (d) show a status light
16. 16.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 200 ms }
    How many times does the LED blink in 4 seconds?
17. 17.Which job needs a motion sensor? (a) warn of a gas leak (b) close a window in rain (c) spot someone walking in (d) open blinds at sunrise
18. 18.True or false: a copper wire is an insulator. (a) False (b) True
19. 19.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 0 % (d) 25 %
20. 20.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V × I (d) P = V + I
21. 21.True or false: a circle with M inside is the symbol for a motor. (a) False (b) True
22. 22.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) the else part (d) neither part
23. 23.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a diode (d) a resistor
24. 24.🔋 A 12 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
25. 25.Which job needs a motor? (a) beep an alarm (b) turn to an exact angle (c) show the temperature (d) spin a robot’s wheels
26. 26.🔺 A current of 25 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
27. 27.🔺 A current of 2.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🔺 A 10 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
29. 29.🔍 Which is the odd one out? (a) a pencil sharpener (b) a Wi-Fi smart plug (c) a Wi-Fi weather station (d) a fitness band with app
30. 30.🌈 A resistor has the colour bands blue, grey, yellow. What is its value in kilo-ohms (kΩ)? =
31. 31.🔺 A current of 50 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
32. 32.Which of these saves electricity? (a) iron one shirt at a time (b) run fans in empty rooms (c) close the fridge quickly (d) use old filament bulbs
33. 33.Which drawing is the symbol for a junction? (a) many long-short pairs (b) triangle against a bar (c) two or more cell symbols (d) a dot where wires meet
34. 34.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) nuclear energy (c) electrical energy (d) wind energy
35. 35.🔺 A current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) read the soil sensor (b) switch the pump on/off (c) wait a few seconds (d) compare with the limit
37. 37.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
38. 38.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the battery (b) the output (c) the process (d) the input
39. 39.True or false: “a break stops every bulb” is true of a series circuit. (a) False (b) True
40. 40.Which of these uses electricity? (a) a battery (b) a power station (c) a computer (d) a wind turbine

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