Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 317 · 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.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 56000 Ω resistor? (a) green-blue-orange (b) green-blue-red (c) blue-green-orange (d) green-blue-yellow
2. 2.🔺 A 20 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
3. 3.🔍 Which is the odd one out? (a) a smart energy meter (b) a wind-up clock (c) a plain table fan (d) a pencil sharpener
4. 4.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
5. 5.True or false: a buzzer mainly gives out light. (a) True (b) False
6. 6.🔋 Does a solar panel give electricity or use electricity? (a) gives electricity (b) uses electricity
7. 7.What does the Wi-Fi link do? (a) measures the real world (b) reads values, decides (c) acts on a command (d) carries the data
8. 8.True or false: a brass key is an insulator. (a) False (b) True
9. 9.🧮 A 2 V battery is joined to 5 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
10. 10.🧮 A 100 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
11. 11.🔍 Which is the odd one out? (a) a table fan (b) a ceiling fan (c) a traffic signal (d) an electric drill
12. 12.🤖 How does a new program get onto a microcontroller board? (a) uploaded over USB (b) drawn with a pen (c) typed on the chip (d) sent by sound
13. 13.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) wait and watch (b) pull them by the hand (c) shout for an adult (d) pour water on them
14. 14.🔍 Which sensor would you use to measure classroom noise? (a) a light sensor (b) a gas sensor (c) a sound sensor (d) a distance sensor
15. 15.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 4 V supply. What current flows (in mA)?
16. 16.🔍 Which is the odd one out? (a) check if temp > 30 (b) the fan starts (c) count button presses (d) decide if soil is dry
17. 17.🔍 Which is the odd one out? (a) build with an adult near (b) fly kites in open fields (c) keep drinks far away (d) poke things in a socket
18. 18.⚡ What does a traffic signal mainly change electricity into? (a) sound (b) light (c) movement (d) heat
19. 19.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?
20. 20.True or false: “used in house wiring” is true of a series circuit. (a) False (b) True
21. 21.⚠️ Who should be with you when you build a circuit? (a) nobody (b) a younger child (c) a trusted adult (d) a stranger online
22. 22.🧮 A 10 Ω resistor is joined in series with two equal 200 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
23. 23.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they get dimmer (c) they all go out (d) they keep glowing
24. 24.🔍 Which sensor would you use to start a fan when hot? (a) a sound sensor (b) a gas sensor (c) a rain sensor (d) a temperature sensor
25. 25.True or false: a laptop uses very little power. (a) False (b) True
26. 26.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 130 readings take?
27. 27.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) little stars (c) dotted circles (d) wavy lines
28. 28.🔁 repeat 5 times { repeat 2 times { beep } }
    How many beeps are there?
29. 29.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a sound sensor (c) a rain sensor (d) a temperature sensor
30. 30.Which of these is an IoT device? (a) a pencil sharpener (b) a plain wall switch (c) a smart energy meter (d) a wind-up clock
31. 31.🔘 Which kind of switch closes near a magnet? (a) a slide switch (b) a push button (c) a toggle switch (d) a reed switch
32. 32.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
33. 33.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the else part (c) both parts (d) the if part
34. 34.Which job is done by the USB port? (a) brings power and code (b) shows the board is on (c) restarts the program (d) keeps the voltage steady
35. 35.🔐 Is it a good or a risky habit to change default passwords? (a) risky habit (b) good habit
36. 36.🧾 A family uses 100 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
37. 37.🔢 To get a sensor reading onto a phone, which comes first: “the board reads it” or “the app shows it”? (a) the app shows it (b) the board reads it
38. 38.True or false: “a break stops every bulb” is true of a parallel circuit. (a) True (b) False
39. 39.🔋 What is a battery? (a) two or more cells joined (b) a kind of bulb (c) a switch with a lid (d) one single wire
40. 40.⏱️ How many milliseconds is a wait of 0.4 seconds?

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