Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 971 · 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.What does a toggle switch do? (a) stays where you flip it (b) works only while pressed (c) closes near a magnet (d) springs back when let go
2. 2.True or false: the voltmeter is joined across a part. (a) False (b) True
3. 3.📶 Digital or analog: a knob turned part way? (a) digital (b) analog
4. 4.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) zero (d) stay the same
5. 5.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) quick and clear for all (c) symbols are heavier (d) to hide the circuit
6. 6.🔋 How many volts does one ordinary torch cell give? (a) 1.5 V (b) 230 V (c) 0.5 V (d) 15 V
7. 7.⚠️ Which power source should children use for electronics projects? (a) a small battery pack (b) a wall socket (c) an inverter socket (d) a mains extension board
8. 8.🔍 Which sensor would you use to spot someone walking in? (a) a motion sensor (b) a light sensor (c) a soil moisture sensor (d) a distance sensor
9. 9.🔌 Is a sound sensor an input or an output for a microcontroller? (a) output (b) input
10. 10.Which drawing is the symbol for an ammeter? (a) a long and a short line (b) triangle, bar and arrows (c) a plain rectangle (d) a circle with A inside
11. 11.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) True (b) False
12. 12.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
13. 13.🔌 Is a woollen thread a conductor or an insulator? (a) a conductor (b) an insulator
14. 14.True or false: a dry cork is a conductor. (a) False (b) True
15. 15.🔌 Is an LED an input or an output for a microcontroller? (a) output (b) input
16. 16.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
17. 17.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = I ÷ V (d) P = V × I
18. 18.🔁 What does a variable do in a program? (a) measures light (b) blinks an LED (c) joins two wires (d) stores a value
19. 19.Which of these is a good habit? (a) accept every permission (b) set a strong password (c) keep factory passwords (d) tap unknown app links
20. 20.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
21. 21.🏠 Which is a smart-home example? (a) a printed map (b) lights on from an app (c) a hand fan (d) a candle in a jar
22. 22.🔁 total = 0
    for i = 1 to 3 { total = total + i }
    What is total at the end?
23. 23.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) one bulb out, all go out (c) each gets the full volts (d) a single current path
24. 24.True or false: to accept every permission is a good habit. (a) False (b) True
25. 25.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) all wires are joined (d) the bulb is unscrewed
26. 26.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
27. 27.🗺️ Before building a project, what should you write down first? (a) the box colour (b) the final price (c) nothing at all (d) inputs and outputs
28. 28.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) the board breaks (c) it deletes itself (d) it starts again
29. 29.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
30. 30.Which of these gives us electricity? (a) an air conditioner (b) a refrigerator (c) a water pump (d) a solar panel
31. 31.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
32. 32.🔍 Which is the odd one out? (a) a plastic straw (b) a dry cork (c) a graphite rod (d) a wooden stick
33. 33.🔋 2 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
34. 34.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V ÷ I (c) R = V + I (d) R = V × I
35. 35.What does a fuse do? (a) blows if current is high (b) lets current go one way (c) beeps for an alarm (d) boosts a small signal
36. 36.🔺 A 4.7 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
37. 37.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
38. 38.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
39. 39.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
40. 40.True or false: a microwave oven has no microcontroller inside. (a) False (b) True

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