Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 188 · 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 of these usually has a microcontroller inside? (a) a toy robot (b) a spinning top (c) a plain wall switch (d) a hand pump
2. 2.🔺 A current of 50 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
3. 3.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
4. 4.Which of these gives us electricity? (a) a cell (b) a refrigerator (c) a computer (d) a television
5. 5.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) wavy lines (c) dotted circles (d) straight lines
6. 6.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
7. 7.🔍 Which is the odd one out? (a) a room heater (b) a mixer grinder (c) an electric toy car (d) an electric drill
8. 8.🔍 Which is the odd one out? (a) an LED lamp (b) a torch (c) a night lamp (d) an electric iron
9. 9.Which of these is a conductor? (a) a safety pin (b) a dry cork (c) a plastic straw (d) a cotton thread
10. 10.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the USB port (b) the voltage regulator (c) the pins (d) the main chip
11. 11.🔺 A current of 3 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
12. 12.🌐 In an IoT system, which part shows data to you? (a) actuator (b) cloud server (c) Wi-Fi (d) phone app
13. 13.Which of these is a risky habit? (a) read app permissions (b) turn off unused gadgets (c) cover unused cameras (d) accept every permission
14. 14.Which of these uses electricity? (a) a wind turbine (b) a battery (c) a computer (d) a solar panel
15. 15.🔌 Is a paper strip a conductor or an insulator? (a) an insulator (b) a conductor
16. 16.True or false: a circle with M inside is the symbol for a bulb. (a) False (b) True
17. 17.🔁 total = 0
    for i = 1 to 5 { total = total + i }
    What is total at the end?
18. 18.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) so all go off together (c) to save copper only (d) each gets full voltage
19. 19.🔐 Why install updates on IoT devices? (a) they fix security holes (b) they delete the Wi-Fi (c) they change the colour (d) they make it heavier
20. 20.🧮 A 0.8 V battery is joined to 5 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
21. 21.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. Does bulb 2 glow? (a) No (b) Yes
22. 22.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
23. 23.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
24. 24.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an oil lamp (c) an LED lamp (d) a candle
25. 25.🔺 A current of 10 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
26. 26.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) No (b) Yes
27. 27.🧩 Which component has coloured bands? (a) LDR (b) resistor (c) motor (d) capacitor
28. 28.True or false: to build with an adult near is not safe. (a) False (b) True
29. 29.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
30. 30.True or false: a rubber band is an insulator. (a) False (b) True
31. 31.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
32. 32.💡 An LED is joined to a 3 V battery through a 1000 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
33. 33.True or false: a potentiometer is a resistance knob. (a) False (b) True
34. 34.🔐 Who should decide which smart devices go in a child’s room? (a) the app’s adverts (b) an online stranger (c) a parent or guardian (d) nobody at all
35. 35.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) capacitor (b) bulb (c) motor (d) resistor
36. 36.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
37. 37.Which of these means the circuit is closed? (a) a cell is taken out (b) the loop is complete (c) a wire has come loose (d) the switch is OFF
38. 38.🤖 Microcontroller or laptop: which one runs many apps at once? (a) laptop (b) microcontroller
39. 39.🔺 A current of 3 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
40. 40.🔘 Which kind of switch works only while pressed? (a) a toggle switch (b) a tilt switch (c) a slide switch (d) a push button

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