Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 223 · 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.🔘 Two switches are in series. When does the bulb glow? (a) when both are ON (b) when both are OFF (c) never (d) when either is ON
2. 2.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a tilt switch (c) a slide switch (d) a push button
3. 3.🌐 A soil sensor sends a reading to an app every 10 minutes. How many readings arrive in 5 hours?
4. 4.🤖 if (sound > 70) { red LED ON } else { green LED ON }
   The sound sensor reads 52. What happens? (a) red LED ON (b) green LED ON
5. 5.⏱️ repeat 8 times { buzzer ON; wait 900 ms; buzzer OFF; wait 700 ms }
   How many milliseconds does this take in all?
6. 6.⚡ What does a buzzer mainly change electricity into? (a) light (b) heat (c) movement (d) sound
7. 7.🔢 To get a sensor reading onto a phone, which comes first: “the board reads it” or “the app shows it”? (a) the board reads it (b) the app shows it
8. 8.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) process (b) input (c) output
9. 9.True or false: “own switch for each bulb” is true of a parallel circuit. (a) False (b) True
10. 10.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
11. 11.Which drawing is the symbol for a resistor? (a) two or more cell symbols (b) a straight line (c) a circle with A inside (d) a small empty box
12. 12.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
13. 13.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) to make it colourful (c) symbols are heavier (d) quick and clear for all
14. 14.⏱️ How many milliseconds is a wait of 4.6 seconds?
15. 15.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) zero (d) bigger
16. 16.True or false: a circle with V inside is the symbol for a switch. (a) True (b) False
17. 17.🧮 Resistors of 470 Ω and 330 Ω are joined in series. What is the total resistance (in ohms)?
18. 18.True or false: the ammeter measures voltage. (a) True (b) False
19. 19.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are ON (b) when either is ON (c) only when both are OFF (d) never
20. 20.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
21. 21.⚡ A device works on 6 V and takes 0.5 A. What is its power (in watts)? =
22. 22.🔺 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
23. 23.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) cell (b) capacitor (c) LED (d) junction
24. 24.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.🔌 Is a safety pin a conductor or an insulator? (a) an insulator (b) a conductor
26. 26.🧮 Resistors of 33 Ω, 220 Ω, 22 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
27. 27.🔋 3 identical 1.2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
28. 28.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is OFF, B is OFF, C is OFF and D is ON. Does the bulb glow? (a) Yes (b) No
29. 29.⚡ Which formula gives electric power? (a) P = V × I (b) P = V ÷ I (c) P = V + I (d) P = I ÷ V
30. 30.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
31. 31.🔐 Why install updates on IoT devices? (a) they change the colour (b) they fix security holes (c) they make it heavier (d) they delete the Wi-Fi
32. 32.🔋 5 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.🔦 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
34. 34.🔍 Which sensor would you use to switch on lamps at dusk? (a) a gas sensor (b) a rain sensor (c) a light sensor (d) a distance sensor
35. 35.🧮 Resistors of 150 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
36. 36.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) switch off empty rooms (c) leave the TV on standby (d) use LED lamps
37. 37.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
38. 38.💡 2 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
39. 39.Which drawing is the symbol for an LED? (a) a dot where wires meet (b) triangle against a bar (c) a straight line (d) triangle, bar and arrows
40. 40.Which drawing is the symbol for a battery? (a) a circle with A inside (b) a dot where wires meet (c) a circle with M inside (d) two or more cell symbols

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