Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 413 · 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: “many paths for current” is true of a series circuit. (a) False (b) True
2. 2.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) LED (b) capacitor (c) battery (d) bulb
3. 3.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 120 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
4. 4.True or false: a spinning top usually has a microcontroller inside. (a) False (b) True
5. 5.🔍 Which is the odd one out? (a) switch off empty rooms (b) set the AC to 24 °C (c) leave fridge door open (d) use daylight to read
6. 6.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
7. 7.🧩 A capacitor in a circuit can … (a) store charge briefly (b) spin a wheel (c) measure heat (d) make light
8. 8.Which job needs a motion sensor? (a) keep an incubator warm (b) open blinds at sunrise (c) water a dry plant (d) spot someone walking in
9. 9.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a cell is taken out (d) all wires are joined
10. 10.💡 3 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
11. 11.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) it is sent by Wi-Fi (b) the app shows it (c) the board reads it (d) the sensor measures
12. 12.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
13. 13.🔍 Which is the odd one out? (a) a Wi-Fi doorbell camera (b) a Wi-Fi smart plug (c) a plain table fan (d) an app-controlled bulb
14. 14.🔺 A current of 0.25 A flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
15. 15.True or false: the flow of charge is measured in watts (W). (a) True (b) False
16. 16.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
17. 17.🔺 A current of 0.2 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
18. 18.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V × I (c) P = V ÷ I (d) P = V + I
19. 19.🧩 Which component lets current go one way? (a) capacitor (b) LED (c) diode (d) motor
20. 20.🧾 A family uses 130 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
21. 21.🔍 Which is the odd one out? (a) a fitness band with app (b) a Wi-Fi smart plug (c) a Wi-Fi doorbell camera (d) a pencil sharpener
22. 22.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 63. What happens? (a) green LED ON (b) red LED ON
23. 23.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) voltmeter (b) capacitor (c) resistor (d) bulb
24. 24.⚡ What does a school bell mainly change electricity into? (a) movement (b) sound (c) heat (d) light
25. 25.🔁 What must there be for a current to flow? (a) a complete loop (b) one loose end (c) a plastic gap (d) a broken path
26. 26.Which job needs a gas sensor? (a) spot someone walking in (b) start a fan when hot (c) close a window in rain (d) warn of a gas leak
27. 27.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
28. 28.🔺 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
29. 29.🔺 A current of 2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
30. 30.🤖 When the main loop of a microcontroller program ends, what happens? (a) it starts again (b) it deletes itself (c) it stops forever (d) the board breaks
31. 31.🔍 Which is the odd one out? (a) a tube light (b) a rice cooker (c) an electric iron (d) a water heater
32. 32.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a parallel circuit (b) a safe circuit (c) an open circuit (d) a short circuit
33. 33.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
34. 34.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1024 (b) 1000 (c) 100 (d) 10
35. 35.What does a transistor do? (a) boosts a small signal (b) turns a fan or wheels (c) blows if current is high (d) senses how hot it is
36. 36.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
37. 37.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 200 ms }
    How many times does the LED blink in 8 seconds?
38. 38.💡 3 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?
39. 39.📏 How many milliamperes (mA) is 1.79 A?
40. 40.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) takes 1 away (d) prints 1

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