Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 727 · 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: a dot where wires meet is the symbol for a resistor. (a) False (b) True
2. 2.🔍 Which sensor would you use to spot someone walking in? (a) a soil moisture sensor (b) a motion sensor (c) a gas sensor (d) a sound sensor
3. 3.🔍 Which is the odd one out? (a) dry your hands first (b) keep drinks far away (c) use small battery cells (d) touch a switch when wet
4. 4.🔘 Which kind of switch works only while pressed? (a) a reed switch (b) a slide switch (c) a toggle switch (d) a push button
5. 5.🔘 Which kind of switch closes near a magnet? (a) a reed switch (b) a tilt switch (c) a slide switch (d) a push button
6. 6.Which of these is true of a series circuit? (a) many paths for current (b) used in house wiring (c) own switch for each bulb (d) one bulb out, all go out
7. 7.Which drawing is the symbol for a motor? (a) a circle with M inside (b) a circle with V inside (c) a dot where wires meet (d) a circle with A inside
8. 8.Which of these mainly makes movement? (a) a room heater (b) a mixer grinder (c) a loudspeaker (d) a rice cooker
9. 9.🔍 Which is the odd one out? (a) a sound sensor (b) a water pump (c) a motor (d) a buzzer
10. 10.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) True (b) False
11. 11.True or false: energy used each second is measured in watts (W). (a) True (b) False
12. 12.💡 Why is house wiring done in parallel? (a) so all go off together (b) to make bulbs dim (c) to save copper only (d) each gets full voltage
13. 13.True or false: an iron nail is an insulator. (a) True (b) False
14. 14.🔺 A current of 40 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🧩 Which part changes electrical energy into movement? (a) a motor (b) an LED (c) a resistor (d) a fuse
16. 16.🌐 Is a fitness band with app an IoT device? (a) not an IoT device (b) an IoT device
17. 17.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to store charge (c) to change its colour (d) to make it brighter
18. 18.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
19. 19.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 16 Ω resistor? (a) brown-blue-black (b) blue-brown-black (c) brown-blue-brown (d) red-blue-black
20. 20.Which job needs a rain sensor? (a) switch on lamps at dusk (b) close a window in rain (c) warn of a gas leak (d) make a parking alarm
21. 21.⚡ What do we call a flow of electric charge through a wire? (a) a magnet (b) electric current (c) sound (d) friction
22. 22.True or false: to accept every permission is a good habit. (a) False (b) True
23. 23.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
24. 24.⚡ What does an electric iron mainly change electricity into? (a) light (b) sound (c) movement (d) heat
25. 25.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) output (b) input
26. 26.🔺 A 12 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
27. 27.🌈 In the resistor colour code, which number does red stand for?
28. 28.Which drawing is the symbol for a switch? (a) a dot where wires meet (b) a circle with an X in it (c) a line lifted at a gap (d) many long-short pairs
29. 29.🗺️ Before building a project, what should you write down first? (a) the final price (b) inputs and outputs (c) nothing at all (d) the box colour
30. 30.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
31. 31.Which of these is the input? (a) a button press (b) decide if soil is dry (c) a buzzer beeps (d) count button presses
32. 32.🔁 repeat 6 times { repeat 4 times { beep } }
    How many beeps are there?
33. 33.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) Yes (b) No
34. 34.🔺 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
35. 35.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) stay the same (d) zero
36. 36.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
37. 37.True or false: a microcontroller needs much more power. (a) True (b) False
38. 38.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
39. 39.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the glass (d) the switch
40. 40.🔘 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 OFF and C is ON. Does the bulb glow? (a) Yes (b) No

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