Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 277 · 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 25 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
2. 2.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
3. 3.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) the else part (d) neither part
4. 4.🔍 Which is the odd one out? (a) use a cable with cuts (b) touch a fallen wire (c) dry your hands first (d) throw cells in a fire
5. 5.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
6. 6.💡 Why does an LED need a resistor in series? (a) to store charge (b) to limit the current (c) to make it brighter (d) to change its colour
7. 7.📏 Which unit measures the flow of charge? (a) watt (W) (b) ohm (Ω) (c) volt (V) (d) ampere (A)
8. 8.True or false: a circle with an X in it is the symbol for a bulb. (a) False (b) True
9. 9.🔁 count = 8
   repeat 9 times { count = count + 6 }
   What is count at the end?
10. 10.Which of these is a risky habit? (a) change default passwords (b) install software updates (c) share the Wi-Fi key (d) turn off unused gadgets
11. 11.🌈 A resistor has the colour bands white, white, red. What is its value (in ohms)?
12. 12.True or false: a buzzer stores a little charge. (a) False (b) True
13. 13.What does a toggle switch do? (a) works only while pressed (b) slides side to side (c) flips up or down (d) springs back when let go
14. 14.⚠️ Which power source should children use for electronics projects? (a) a mains extension board (b) an inverter socket (c) a wall socket (d) a small battery pack
15. 15.💡 2 identical bulbs are joined in series with a 6 V battery (ideal wires). How many volts does each bulb get? =
16. 16.Which drawing is the symbol for a cell? (a) a plain rectangle (b) a long and a short line (c) a circle with an X in it (d) a circle with V inside
17. 17.🧩 Which component glows using little power? (a) resistor (b) motor (c) LED (d) buzzer
18. 18.Which of these is not an IoT device? (a) a plain wall switch (b) a smart energy meter (c) a Wi-Fi smart plug (d) a Wi-Fi weather station
19. 19.🔺 A current of 0.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
20. 20.What does a push button do? (a) stays where you flip it (b) closes near a magnet (c) slides side to side (d) springs back when let go
21. 21.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
22. 22.🧾 A 500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
23. 23.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
24. 24.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.Which job is done by the power LED? (a) brings power and code (b) connect sensors and LEDs (c) keeps the voltage steady (d) shows the board is on
26. 26.True or false: a reed switch stays where you flip it. (a) False (b) True
27. 27.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
28. 28.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the input (c) the process (d) the battery
29. 29.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop
30. 30.🧩 Which component senses how bright it is? (a) diode (b) motor (c) potentiometer (d) LDR
31. 31.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 26 °C. What is shown? (a) Cool (b) Hot (c) Warm
32. 32.True or false: a microcontroller runs many apps at once. (a) True (b) False
33. 33.Which of these means the circuit is closed? (a) a cell is taken out (b) all wires are joined (c) the switch is OFF (d) a wire has come loose
34. 34.⚠️ Is it safe to fly kites in open fields? (a) safe (b) not safe
35. 35.Which of these saves electricity? (a) run fans in empty rooms (b) use old filament bulbs (c) switch off empty rooms (d) leave the TV on standby
36. 36.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
37. 37.🔢 To plan an electronics project, which is the LAST step? (a) pick a problem to solve (b) list inputs and outputs (c) test it and fix it (d) draw the circuit diagram
38. 38.⚡ What does a ceiling fan mainly change electricity into? (a) light (b) heat (c) movement (d) sound
39. 39.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
40. 40.📏 How many amperes (A) is 100 mA? =

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