Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 637 · 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.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) zero (d) stay the same
2. 2.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
3. 3.🔘 A bulb and a cell are joined through 3 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
4. 4.💡 3 identical bulbs are joined in series with a 7.5 V battery (ideal wires). How many volts does each bulb get? =
5. 5.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) does not light (b) may burn out (c) lights up
6. 6.Which of these is a conductor? (a) a cotton thread (b) a brass key (c) a glass marble (d) a ceramic cup
7. 7.🔍 Which is the odd one out? (a) reuse one password (b) read app permissions (c) log out of shared phones (d) share only needed data
8. 8.Which drawing is the symbol for a motor? (a) a circle with A inside (b) triangle, bar and arrows (c) a plain rectangle (d) a circle with M inside
9. 9.📏 Which unit measures current? (a) watt (W) (b) volt (V) (c) ampere (A) (d) ohm (Ω)
10. 10.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
11. 11.True or false: a laptop needs much more power. (a) False (b) True
12. 12.🔘 Which kind of switch closes near a magnet? (a) a push button (b) a tilt switch (c) a reed switch (d) a toggle switch
13. 13.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
14. 14.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 12 V (c) 1.5 V (d) 9 V
15. 15.🔺 A 2.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
16. 16.🔁 count = 5
    while (count < 17) { count = count + 4 }
    How many times does the loop run?
17. 17.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
18. 18.💡 2 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
19. 19.💡 4 identical bulbs are joined in series with a 16 V battery (ideal wires). How many volts does each bulb get? =
20. 20.Which of these is measured in volts (V)? (a) power (b) the flow of charge (c) the push of a cell (d) how much a part resists
21. 21.🔍 Which is the odd one out? (a) a safety pin (b) a brass key (c) a metal paper clip (d) a woollen thread
22. 22.Which of these is true of a parallel circuit? (a) one bulb out, all go out (b) bulbs share the voltage (c) each gets the full volts (d) a break stops every bulb
23. 23.🧮 Resistors of 10 Ω and 330 Ω are joined in series. What is the total resistance (in ohms)?
24. 24.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) junction (b) voltmeter (c) resistor (d) switch
25. 25.🔘 What does a switch do in a circuit? (a) stores current (b) opens or closes the loop (c) changes the voltage (d) makes electricity
26. 26.Which of these uses electricity? (a) a cell (b) a battery (c) a power station (d) a water pump
27. 27.📏 In the water-pipe picture of a circuit, resistance is like … (a) a bigger tank (b) a narrow pipe (c) the flow of water (d) the water pressure
28. 28.🤖 if (temperature > 35) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 27 °C. What is shown? (a) Cool (b) Warm (c) Hot
29. 29.Which of these usually has a microcontroller inside? (a) a candle (b) a spinning top (c) a bicycle bell (d) a washing machine
30. 30.💡 3 identical bulbs are joined in parallel across a 1.5 V battery (ideal wires). How many volts does each bulb get? =
31. 31.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by aluminium foil. Does the bulb glow? (a) Yes (b) No
32. 32.📏 Which unit measures the push of a cell? (a) ampere (A) (b) ohm (Ω) (c) watt (W) (d) volt (V)
33. 33.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) a smaller voltage (c) no voltage (d) the same voltage
34. 34.📶 A pin set LOW gives about … (a) 5 V (b) 1.5 V (c) 0 V (d) 9 V
35. 35.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) waits 500 seconds (c) turns the LED off (d) blinks 500 times
36. 36.Which of these has no microcontroller inside? (a) a digital thermometer (b) a toy robot (c) a bicycle bell (d) a digital alarm clock
37. 37.🔘 Which kind of switch works only while pressed? (a) a tilt switch (b) a toggle switch (c) a reed switch (d) a push button
38. 38.True or false: on a cell, “the flat end” means the − (negative) end. (a) True (b) False
39. 39.⚡ A 12 W device works on 24 V. What current does it take (in amperes)? =
40. 40.💡 3 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 3 glow? (a) No (b) Yes

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