Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 264 · 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 of these is true of a series circuit? (a) each gets the full volts (b) a single current path (c) used in house wiring (d) one out, the rest glow
2. 2.✏️ 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
3. 3.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) lights up (c) does not light
4. 4.🔐 Is it a good or a risky habit to post your live location? (a) good habit (b) risky habit
5. 5.🔍 Which is the odd one out? (a) a steel coin (b) a steel spoon (c) a brass key (d) a woollen thread
6. 6.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is OFF. Does the bulb glow? (a) No (b) Yes
7. 7.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) input (b) output (c) process
8. 8.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 8 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) OFF (b) ON
9. 9.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) output (b) input (c) process
10. 10.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 49. What happens? (a) green LED ON (b) red LED ON
11. 11.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 60 (d) 100
12. 12.🧩 Which component turns a fan or wheels? (a) buzzer (b) motor (c) resistor (d) potentiometer
13. 13.🧩 Which part changes electrical energy into movement? (a) a fuse (b) an LED (c) a resistor (d) a motor
14. 14.💡 A red LED uses 2 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
15. 15.🔌 Is a woollen thread a conductor or an insulator? (a) a conductor (b) an insulator
16. 16.True or false: a buzzer beeps for an alarm. (a) True (b) False
17. 17.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
18. 18.⚡ Power tells us … (a) the size of a cell (b) the colour of light (c) energy used each second (d) the length of a wire
19. 19.🧮 A 20 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
20. 20.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) the board reads it (b) the app shows it (c) it is sent by Wi-Fi (d) the sensor measures
21. 21.🧾 A family uses 130 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
22. 22.🔍 Which is the odd one out? (a) a plain wall switch (b) a paper calendar (c) an app-controlled bulb (d) a pencil sharpener
23. 23.🧩 A capacitor in a circuit can … (a) make light (b) measure heat (c) spin a wheel (d) store charge briefly
24. 24.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
25. 25.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 100 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
26. 26.Which of these is true of a series circuit? (a) used in house wiring (b) a break stops every bulb (c) each gets the full volts (d) one out, the rest glow
27. 27.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a capacitor (d) a resistor
28. 28.🔍 A distance sensor sends a sound pulse and hears the echo 14 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
29. 29.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
30. 30.⚠️ Why must we never touch switches with wet hands? (a) it spoils the paint (b) water makes it cold (c) water carries current (d) it is just untidy
31. 31.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
32. 32.🔁 What does “count = count + 1” do? (a) takes 1 away (b) prints 1 (c) sets count to 1 (d) adds 1 to count
33. 33.True or false: “the fan starts” is the output. (a) False (b) True
34. 34.🧾 A family uses 30 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
35. 35.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
36. 36.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) wavy lines (c) dotted circles (d) little stars
37. 37.True or false: a smart watch has no microcontroller inside. (a) True (b) False
38. 38.🔁 x = 1
    repeat 2 times { x = x × 2 }
    What is x at the end?
39. 39.🌐 In an IoT system, which part carries the data? (a) actuator (b) Wi-Fi (c) cloud server (d) microcontroller
40. 40.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) becomes zero (d) gets bigger

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