Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 499 · 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.💡 2 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
2. 2.Which of these uses electricity? (a) a water pump (b) a cell (c) a power station (d) a solar panel
3. 3.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = I ÷ V (d) P = V ÷ I
4. 4.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) turns the LED off (c) blinks 500 times (d) waits 500 seconds
5. 5.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
6. 6.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
7. 7.🔁 Is the circuit closed or open if all wires are joined? (a) closed (b) open
8. 8.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) LED (b) resistor (c) bulb (d) diode
9. 9.True or false: to water a dry plant, use a rain sensor. (a) True (b) False
10. 10.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a buzzer (d) a capacitor
11. 11.True or false: if a cell is taken out, the circuit is closed and current flows. (a) True (b) False
12. 12.📏 Which unit measures resistance? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
13. 13.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
14. 14.True or false: a rubber band is a conductor. (a) False (b) True
15. 15.Which of these is safe? (a) poke things in a socket (b) use a cable with cuts (c) touch a fallen wire (d) take cells out after use
16. 16.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
17. 17.True or false: on a cell, “the longer symbol line” means the − (negative) end. (a) True (b) False
18. 18.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is ON, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
19. 19.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
20. 20.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.True or false: a long and a short line is the symbol for a cell. (a) True (b) False
22. 22.What does a push button do? (a) works only while pressed (b) slides side to side (c) stays where you flip it (d) closes when tipped over
23. 23.Which drawing is the symbol for a switch? (a) a circle with V inside (b) a circle with A inside (c) a long and a short line (d) a line lifted at a gap
24. 24.True or false: “a door: open or shut” is a digital signal. (a) False (b) True
25. 25.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 4 hours?
26. 26.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the one nearest an end (d) the widest gap
27. 27.🔁 repeat 4 times { repeat 3 times { beep } }
    How many beeps are there?
28. 28.💡 Why does an LED need a resistor in series? (a) to store charge (b) to make it brighter (c) to change its colour (d) to limit the current
29. 29.⏱️ loop forever { LED ON; wait 600 ms; LED OFF; wait 1400 ms }
    How many times does the LED blink in 2 seconds?
30. 30.What does a tilt switch do? (a) closes near a magnet (b) flips up or down (c) springs back when let go (d) closes when tipped over
31. 31.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 3 hours?
32. 32.🔘 Two switches are in series. When does the bulb glow? (a) never (b) when both are OFF (c) when both are ON (d) when either is ON
33. 33.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) the same voltage (c) no voltage (d) half the voltage
34. 34.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the USB port (b) the voltage regulator (c) the pins (d) the reset button
35. 35.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 5 V supply. What current flows (in mA)?
36. 36.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) switch the pump on/off (b) read the soil sensor (c) wait a few seconds
37. 37.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
38. 38.🔦 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) Yes (b) No
39. 39.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
40. 40.🧮 Resistors of 330 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?

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