Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 504 · 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 lamp gives the same light for the least power? (a) a filament bulb (b) an oil lamp (c) an LED lamp (d) a candle
2. 2.🧮 Two resistors in parallel give a total that is … (a) always zero (b) more than either one (c) less than either one (d) their sum
3. 3.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
4. 4.🔺 A current of 25 mA flows when 6.25 V is joined across a resistor. What is its resistance (in ohms)?
5. 5.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
6. 6.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
7. 7.Which of these mainly gives out heat? (a) a ceiling fan (b) a rice cooker (c) a street light (d) a loudspeaker
8. 8.💡 A battery lights 2 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) brighter (c) the same
9. 9.True or false: on a cell, “the flat end” means the + (positive) end. (a) True (b) False
10. 10.Which of these is the process? (a) a temperature reading (b) a buzzer beeps (c) a light level reading (d) count button presses
11. 11.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) energy used each second (d) the length of a wire
12. 12.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) by Wi-Fi (d) in parallel
13. 13.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
14. 14.⚡ What does a torch mainly change electricity into? (a) movement (b) light (c) sound (d) heat
15. 15.📶 Digital or analog: a knob turned part way? (a) analog (b) digital
16. 16.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) output (b) input (c) process
17. 17.🔺 A current of 2.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
18. 18.🔘 When a switch is ON, the circuit is … (a) open (b) cut (c) broken (d) closed
19. 19.Which drawing is the symbol for a battery? (a) two or more cell symbols (b) a circle with a cross (c) a circle with an X in it (d) two equal parallel lines
20. 20.⏱️ How many milliseconds is a wait of 3.9 seconds?
21. 21.Which of these wastes electricity? (a) use daylight to read (b) use old filament bulbs (c) close the fridge quickly (d) unplug idle chargers
22. 22.🔋 2 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
23. 23.📏 How many amperes (A) is 780 mA? =
24. 24.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
25. 25.🔁 total = 0
    for i = 1 to 10 { total = total + i }
    What is total at the end?
26. 26.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) it does not matter (b) both of them (c) only one (d) none
27. 27.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
28. 28.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the board reads it (b) the app shows it (c) it is sent by Wi-Fi (d) the sensor measures
29. 29.True or false: a resistor blows if current is high. (a) True (b) False
30. 30.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
31. 31.🔍 Which is the odd one out? (a) close the fridge quickly (b) set the AC to 24 °C (c) run fans in empty rooms (d) use LED lamps
32. 32.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
33. 33.🔍 Which is the odd one out? (a) a plastic ruler (b) a paper strip (c) a rubber eraser (d) a safety pin
34. 34.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 42000 Ω resistor? (a) yellow-red-red (b) red-yellow-orange (c) yellow-red-yellow (d) yellow-red-orange
35. 35.True or false: the ammeter measures voltage. (a) False (b) True
36. 36.True or false: a laptop uses very little power. (a) True (b) False
37. 37.What does the Wi-Fi link do? (a) stores data online (b) acts on a command (c) measures the real world (d) carries the data
38. 38.⚡ A 4.5 W device works on 9 V. What current does it take (in amperes)? =
39. 39.True or false: “one out, the rest glow” is true of a parallel circuit. (a) True (b) False
40. 40.True or false: a circle with A inside is the symbol for a switch. (a) False (b) True

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