Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 332 · 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: a tube light mainly gives out light. (a) False (b) True
2. 2.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) not joined (c) in series (d) by Wi-Fi
3. 3.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) the size of a cell (d) energy used each second
4. 4.Which job needs a motor? (a) beep an alarm (b) spin a robot’s wheels (c) turn to an exact angle (d) open a gate to 90°
5. 5.🔍 Which is the odd one out? (a) a battery torch (b) an app-controlled bulb (c) a wind-up clock (d) a plain table fan
6. 6.True or false: a fuse blows if current is high. (a) True (b) False
7. 7.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
8. 8.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) Yes (b) No
9. 9.⚙️ What is an actuator? (a) an output that acts (b) a program (c) a sensor (d) a battery
10. 10.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the board reads it (b) the cloud stores it (c) the sensor measures (d) the app shows it
11. 11.🧩 Which component blows if current is high? (a) buzzer (b) fuse (c) motor (d) LDR
12. 12.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) shout for an adult (b) pour water on them (c) wait and watch (d) pull them by the hand
13. 13.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the battery (c) the process (d) the input
14. 14.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
15. 15.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the shorter line (c) the longer line (d) neither line
16. 16.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 9400 Ω resistor? (a) yellow-white-red (b) white-yellow-brown (c) white-yellow-red (d) white-yellow-orange
17. 17.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 90 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
18. 18.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) plastic makes current (c) plastic is a conductor (d) to make them heavy
19. 19.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 4 V supply. What current flows (in mA)?
20. 20.🔺 A 6.25 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
21. 21.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a resistor (c) an LED (d) a motor
22. 22.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) the board reads it (b) the sensor measures (c) it is sent by Wi-Fi (d) the app shows it
23. 23.🔋 Does a bicycle dynamo give electricity or use electricity? (a) gives electricity (b) uses electricity
24. 24.🧩 Which component makes things spin? (a) motor (b) LDR (c) resistor (d) buzzer
25. 25.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
26. 26.True or false: a brass key is an insulator. (a) False (b) True
27. 27.🧮 A 22 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
28. 28.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 9 seconds?
29. 29.🔍 Which is the odd one out? (a) a fitness band with app (b) a pencil sharpener (c) a smart energy meter (d) an app-controlled bulb
30. 30.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) No (b) Yes
31. 31.True or false: if all wires are joined, the circuit is closed and current flows. (a) False (b) True
32. 32.True or false: a diode makes a beeping sound. (a) False (b) True
33. 33.⏱️ How many milliseconds is a wait of 0.4 seconds?
34. 34.True or false: the voltmeter is joined in series. (a) True (b) False
35. 35.💡 Why is house wiring done in parallel? (a) so all go off together (b) to make bulbs dim (c) each gets full voltage (d) to save copper only
36. 36.🔺 A current of 20 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
37. 37.Which of these is the output? (a) a temperature reading (b) count button presses (c) a buzzer beeps (d) decide if soil is dry
38. 38.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 50 ms }
    How many milliseconds does one blink (ON + OFF) take?
39. 39.Which of these wastes electricity? (a) switch off empty rooms (b) use old filament bulbs (c) close the fridge quickly (d) set the AC to 24 °C
40. 40.🔋 Does a solar panel give electricity or use electricity? (a) gives electricity (b) uses electricity

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