Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 773 · 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.🔺 A current of 40 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
2. 2.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
3. 3.📏 How many milliamperes (mA) make 1 ampere? (a) 10 (b) 1000 (c) 100 (d) 60
4. 4.Which of these is a risky habit? (a) install software updates (b) reuse one password (c) set a strong password (d) set up with a parent
5. 5.⚡ A 1.8 W device works on 9 V. What current does it take (in amperes)? =
6. 6.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
7. 7.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
8. 8.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) a fuse (c) an input (d) an output
9. 9.🔺 A 2 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
10. 10.📏 Which unit measures the push of a cell? (a) watt (W) (b) volt (V) (c) ohm (Ω) (d) ampere (A)
11. 11.Which job needs a soil moisture sensor? (a) start a fan when hot (b) switch on lamps at dusk (c) keep an incubator warm (d) water a dry plant
12. 12.🔺 A current of 50 mA flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
13. 13.Which of these is a good habit? (a) accept every permission (b) tap unknown app links (c) ignore update messages (d) set a strong password
14. 14.What does a motor do? (a) glows using little power (b) has coloured bands (c) stores a little charge (d) turns a fan or wheels
15. 15.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
16. 16.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
17. 17.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) wait a few seconds (b) compare with the limit (c) read the soil sensor (d) switch the pump on/off
18. 18.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is OFF and C is ON. Does the bulb glow? (a) No (b) Yes
19. 19.🧩 A capacitor in a circuit can … (a) measure heat (b) store charge briefly (c) make light (d) spin a wheel
20. 20.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) smaller (c) bigger (d) zero
21. 21.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a bulb (b) a long wire (c) a plug top (d) a fuse or MCB
22. 22.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the voltage regulator (b) the main chip (c) the power LED (d) the pins
23. 23.Which of these has no microcontroller inside? (a) a washing machine (b) a digital thermometer (c) a candle (d) a toy robot
24. 24.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) False (b) True
25. 25.⏱️ A program says “wait 1750 ms”. How many seconds is that? =
26. 26.True or false: current is measured in amperes (A). (a) False (b) True
27. 27.🔁 count = 1
    repeat 3 times { count = count + 10 }
    What is count at the end?
28. 28.🔗 Series or parallel circuit: “each gets the full volts”? (a) parallel (b) series
29. 29.🗺️ Before building a project, what should you write down first? (a) the final price (b) the box colour (c) nothing at all (d) inputs and outputs
30. 30.⚡ A device works on 9 V and takes 3 A. What is its power (in watts)? =
31. 31.🔌 Is a brass key a conductor or an insulator? (a) an insulator (b) a conductor
32. 32.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
33. 33.🔍 Which is the odd one out? (a) use small battery cells (b) dry your hands first (c) use a cable with cuts (d) fly kites in open fields
34. 34.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) an LED (d) a motor
35. 35.True or false: to share camera links is a good habit. (a) True (b) False
36. 36.True or false: on a cell, “the flat end” means the − (negative) end. (a) True (b) False
37. 37.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
38. 38.⏱️ loop forever { LED ON; wait 400 ms; LED OFF; wait 800 ms }
    How many milliseconds does one blink (ON + OFF) take?
39. 39.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
40. 40.🧮 Four equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?

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