Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 330 · 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: “an alert on the phone” is the output. (a) False (b) True
2. 2.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) True (b) False
3. 3.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
4. 4.Which job is done by the voltage regulator? (a) restarts the program (b) keeps the voltage steady (c) brings power and code (d) runs the program
5. 5.🔘 Which kind of switch springs back when let go? (a) a toggle switch (b) a tilt switch (c) a push button (d) a slide switch
6. 6.Which of these is true of a series circuit? (a) one bulb out, all go out (b) own switch for each bulb (c) each gets the full volts (d) one out, the rest glow
7. 7.🔺 A current of 50 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
8. 8.🔋 8 identical 1.5 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
9. 9.True or false: “used in house wiring” is true of a parallel circuit. (a) False (b) True
10. 10.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = V × I (d) R = I ÷ V
11. 11.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the voltage regulator (b) the reset button (c) the USB port (d) the power LED
12. 12.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) in series (c) not joined (d) by Wi-Fi
13. 13.True or false: to poke things in a socket is not safe. (a) False (b) True
14. 14.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
15. 15.Which of these is an input? (a) a buzzer (b) a push button (c) a servo motor (d) an LED
16. 16.🌈 A resistor has the colour bands white, blue, red. What is its value in kilo-ohms (kΩ)? =
17. 17.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
18. 18.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 15 cm. What happens? (a) buzzer beeps (b) buzzer is silent
19. 19.🔘 When a switch is ON, the circuit is … (a) open (b) broken (c) closed (d) cut
20. 20.🔍 Which sensor would you use to close a window in rain? (a) a temperature sensor (b) a motion sensor (c) a rain sensor (d) a light sensor
21. 21.⚡ What does a street light mainly change electricity into? (a) sound (b) light (c) heat (d) movement
22. 22.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the process (c) the battery (d) the input
23. 23.True or false: a circle with an X in it is the symbol for a motor. (a) True (b) False
24. 24.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
25. 25.🧮 Resistors of 50 Ω, 150 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
26. 26.🔘 What does a switch do in a circuit? (a) makes electricity (b) changes the voltage (c) opens or closes the loop (d) stores current
27. 27.🔍 Which is the odd one out? (a) use a cable with cuts (b) dry your hands first (c) use mains for a project (d) poke things in a socket
28. 28.⚡ A device works on 3 V and takes 1.5 A. What is its power (in watts)? =
29. 29.⚡ Which formula gives electric power? (a) P = V × I (b) P = I ÷ V (c) P = V ÷ I (d) P = V + I
30. 30.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 10 (c) 1000 (d) 100
31. 31.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) only when both are OFF (c) when either is ON (d) never
32. 32.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
33. 33.Which of these is an input? (a) a servo motor (b) a water pump (c) a turning knob (d) a speaker
34. 34.⚡ A solar panel changes which kind of energy into electricity? (a) chemical energy (b) wind energy (c) sound energy (d) light energy
35. 35.Which of these is true of a series circuit? (a) own switch for each bulb (b) bulbs share the voltage (c) one out, the rest glow (d) many paths for current
36. 36.True or false: to use LED lamps saves electricity. (a) True (b) False
37. 37.True or false: if a cell is taken out, the circuit is open and no current flows. (a) True (b) False
38. 38.True or false: “a soil moisture reading” is the process. (a) True (b) False
39. 39.⚡ What does a tube light mainly change electricity into? (a) movement (b) light (c) sound (d) heat
40. 40.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False

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