Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 924 · 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.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = V × I (d) P = I ÷ V
2. 2.True or false: a long and a short line is the symbol for a wire. (a) True (b) False
3. 3.⚙️ What is an actuator? (a) a sensor (b) a battery (c) an output that acts (d) a program
4. 4.Which of these is a risky habit? (a) set up with a parent (b) log out of shared phones (c) accept every permission (d) turn off unused gadgets
5. 5.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a battery torch (c) a fitness band with app (d) a Wi-Fi doorbell camera
6. 6.True or false: a reed switch closes near a magnet. (a) False (b) True
7. 7.True or false: “one out, the rest glow” is true of a series circuit. (a) False (b) True
8. 8.⚡ A fan changes electrical energy mainly into which kind of energy? (a) sound energy (b) movement energy (c) light energy (d) chemical energy
9. 9.🔍 Which sensor would you use to switch on lamps at dusk? (a) a soil moisture sensor (b) a distance sensor (c) a temperature sensor (d) a light sensor
10. 10.🔘 Which kind of switch flips up or down? (a) a toggle switch (b) a slide switch (c) a reed switch (d) a tilt switch
11. 11.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
12. 12.🌈 Which band is read first on a resistor? (a) any band (b) the one nearest an end (c) the gold band (d) the widest gap
13. 13.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
14. 14.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) wire (b) cell (c) resistor (d) capacitor
15. 15.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 100 (c) 10 (d) 1000
16. 16.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) bulbs share the voltage (c) one bulb out, all go out (d) one out, the rest glow
17. 17.🔺 A current of 25 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
18. 18.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) an output (c) a power source (d) a fuse
19. 19.⚠️ Who should be with you when you build a circuit? (a) a trusted adult (b) a stranger online (c) nobody (d) a younger child
20. 20.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.🌈 A resistor has the colour bands grey, orange, red. What is its value in kilo-ohms (kΩ)? =
22. 22.True or false: to use daylight to read wastes electricity. (a) False (b) True
23. 23.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) process (b) output (c) input
24. 24.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
25. 25.True or false: “a break stops every bulb” is true of a parallel circuit. (a) True (b) False
26. 26.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
27. 27.🔋 How many 2 V cells must be joined in series to give 10 V?
28. 28.🌐 In an IoT system, which part measures the real world? (a) Wi-Fi (b) actuator (c) microcontroller (d) sensor
29. 29.🧮 A 68 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
30. 30.💡 A battery lights 3 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
31. 31.🔺 A current of 0.1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
32. 32.🔍 Which is the odd one out? (a) a temperature sensor (b) a servo motor (c) a light sensor (d) a push button
33. 33.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) Yes (b) No
34. 34.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) stores a value (d) joins two wires
35. 35.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 97. What happens? (a) lamp ON (b) lamp OFF
36. 36.Which of these wastes electricity? (a) unplug idle chargers (b) switch off empty rooms (c) use LED lamps (d) leave fridge door open
37. 37.💡 An LED is joined to a 5 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) does not light (c) may burn out
38. 38.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I × R (c) V = I + R (d) V = R ÷ I
39. 39.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) each gets full voltage (c) to save copper only (d) so all go off together
40. 40.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 560 Ω resistor? (a) blue-green-brown (b) green-blue-red (c) green-blue-black (d) green-blue-brown

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