Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 151 · 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: to use daylight to read saves electricity. (a) False (b) True
2. 2.📏 Which unit measures power? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)
3. 3.🔺 A current of 10 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🔺 A 6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
5. 5.True or false: the voltmeter measures current. (a) True (b) False
6. 6.🔺 A current of 40 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
7. 7.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
8. 8.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
9. 9.🧮 Five equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
10. 10.🔁 count = 9
    repeat 8 times { count = count + 2 }
    What is count at the end?
11. 11.Which of these mainly makes sound? (a) a table fan (b) an LED lamp (c) a loudspeaker (d) a night lamp
12. 12.🔍 Which is the odd one out? (a) the fan starts (b) a soil moisture reading (c) an LED lights up (d) the pump turns on
13. 13.🧮 A 22 V battery is joined to 12 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
14. 14.⚡ What does a toaster mainly change electricity into? (a) sound (b) movement (c) light (d) heat
15. 15.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) wire (b) capacitor (c) junction (d) cell
16. 16.True or false: “a button press” is the input. (a) False (b) True
17. 17.🔍 An object is 170 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
18. 18.What does the phone app do? (a) acts on a command (b) measures the real world (c) shows data to you (d) stores data online
19. 19.🔺 A 16 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
20. 20.True or false: to use a cable with cuts is safe. (a) True (b) False
21. 21.🔍 An object is 136 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
22. 22.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
23. 23.🔍 Which is the odd one out? (a) install software updates (b) log out of shared phones (c) change default passwords (d) keep factory passwords
24. 24.Which of these is true of a series circuit? (a) many paths for current (b) used in house wiring (c) a single current path (d) one out, the rest glow
25. 25.True or false: the ammeter measures current. (a) True (b) False
26. 26.🧾 A family uses 160 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
27. 27.True or false: a plain rectangle is the symbol for an ammeter. (a) True (b) False
28. 28.🔺 A current of 0.2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
29. 29.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) a wire is cut (d) a wire has come loose
30. 30.🔍 Which is the odd one out? (a) a sound sensor (b) a servo motor (c) a keypad (d) a turning knob
31. 31.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the power LED (b) the main chip (c) the reset button (d) the pins
32. 32.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
33. 33.📏 How many watts (W) is 4 kW?
34. 34.What does a push button do? (a) closes near a magnet (b) closes when tipped over (c) works only while pressed (d) slides side to side
35. 35.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) little stars (c) dotted circles (d) straight lines
36. 36.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
37. 37.🔌 Is a turning knob an input or an output for a microcontroller? (a) output (b) input
38. 38.📏 How many milliamperes (mA) is 2.33 A?
39. 39.Which job is done by the power LED? (a) connect sensors and LEDs (b) brings power and code (c) runs the program (d) shows the board is on
40. 40.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) an oil lamp (d) a candle

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