Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 337 · 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.🤖 if (temperature > 30) { fan ON } else { fan OFF }
   The temperature sensor reads 36 °C. What happens? (a) fan ON (b) fan OFF
2. 2.🧩 Which part changes electrical energy into movement? (a) a fuse (b) an LED (c) a motor (d) a resistor
3. 3.🔺 A current of 50 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔺 A 3 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
5. 5.🔍 Which sensor would you use to water a dry plant? (a) a rain sensor (b) a soil moisture sensor (c) a temperature sensor (d) a motion sensor
6. 6.Which of these is the process? (a) a light level reading (b) the pump turns on (c) a button press (d) decide if soil is dry
7. 7.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) wait a few seconds (b) switch the pump on/off (c) read the soil sensor
8. 8.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) LED (b) bulb (c) ammeter (d) battery
9. 9.🔋 4 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
10. 10.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
11. 11.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
12. 12.🧩 Which component smooths a wobbly supply? (a) motor (b) transistor (c) LDR (d) capacitor
13. 13.True or false: one tall, one short bar is the symbol for a resistor. (a) True (b) False
14. 14.True or false: “an alert on the phone” is the input. (a) True (b) False
15. 15.💡 In a series circuit, how many paths does the current have? (a) none (b) two (c) one (d) one for each bulb
16. 16.📏 How many watts (W) is 2.2 kW?
17. 17.⏱️ A program says “wait 7500 ms”. How many seconds is that? =
18. 18.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
19. 19.🧾 A family uses 70 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
20. 20.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) cell (b) diode (c) bulb (d) voltmeter
21. 21.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
22. 22.Which of these is a good habit? (a) share the Wi-Fi key (b) set up with a parent (c) share camera links (d) keep factory passwords
23. 23.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
24. 24.🤖 “if (A AND B)” is true when … (a) both are false (b) only B is true (c) both A and B are true (d) only A is true
25. 25.What does a reed switch do? (a) springs back when let go (b) closes near a magnet (c) slides side to side (d) flips up or down
26. 26.🔐 Is it a good or a risky habit to log out of shared phones? (a) risky habit (b) good habit
27. 27.🧩 Which component is a resistance knob? (a) buzzer (b) transistor (c) motor (d) potentiometer
28. 28.True or false: a laptop has no screen of its own. (a) False (b) True
29. 29.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 60 (c) 1000 (d) 10
30. 30.Which of these is the output? (a) an alert on the phone (b) a button press (c) a soil moisture reading (d) decide if soil is dry
31. 31.What does an LED do? (a) glows using little power (b) stores a little charge (c) senses how hot it is (d) has coloured bands
32. 32.🔋 8 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
33. 33.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “wait a few seconds”? (a) wait a few seconds (b) read the soil sensor
34. 34.🔍 Which is the odd one out? (a) aluminium foil (b) a ceramic cup (c) a rubber band (d) a rubber eraser
35. 35.📏 Which unit measures the push of a cell? (a) volt (V) (b) watt (W) (c) ohm (Ω) (d) ampere (A)
36. 36.Which of these is true of a series circuit? (a) own switch for each bulb (b) used in house wiring (c) one bulb out, all go out (d) one out, the rest glow
37. 37.Which of these is a conductor? (a) a paper strip (b) a cotton thread (c) a copper wire (d) a glass marble
38. 38.🔁 x = 2
    repeat 3 times { x = x × 2 }
    What is x at the end?
39. 39.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) the switch is OFF (d) all wires are joined
40. 40.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) the colour of light (d) energy used each second

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