Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 287 · 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.What does a toggle switch do? (a) closes near a magnet (b) springs back when let go (c) works only while pressed (d) stays where you flip it
2. 2.🌈 Which band is read first on a resistor? (a) the gold band (b) the widest gap (c) any band (d) the one nearest an end
3. 3.⚠️ Is it safe to poke things in a socket? (a) not safe (b) safe
4. 4.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) leave fridge door open (c) leave the TV on standby (d) run fans in empty rooms
5. 5.🔐 Which is the strongest password for a home smart camera? (a) admin (b) 123456 (c) password (d) Tiger#Lamp42!Moon
6. 6.Which of these uses electricity? (a) a refrigerator (b) a cell (c) a battery (d) a generator
7. 7.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
8. 8.True or false: to switch on lamps at dusk, use a light sensor. (a) True (b) False
9. 9.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
10. 10.💡 An LED is joined to a 5 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) does not light (c) lights up
11. 11.🌈 In the resistor colour code, which number does yellow stand for?
12. 12.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 ampere (c) 1 volt (d) 1 watt
14. 14.🔁 repeat 5 times { repeat 3 times { beep } }
    How many beeps are there?
15. 15.🔁 What does a variable do in a program? (a) blinks an LED (b) joins two wires (c) measures light (d) stores a value
16. 16.⚡ Power tells us … (a) the colour of light (b) energy used each second (c) the size of a cell (d) the length of a wire
17. 17.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 62 %. What happens? (a) pump ON (b) pump OFF
18. 18.🤖 How does a new program get onto a microcontroller board? (a) typed on the chip (b) uploaded over USB (c) drawn with a pen (d) sent by sound
19. 19.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.🔐 Is it a good or a risky habit to keep factory passwords? (a) good habit (b) risky habit
21. 21.🔢 To plan an electronics project, which comes first: “build it with an adult” or “test it and fix it”? (a) build it with an adult (b) test it and fix it
22. 22.💡 5 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
23. 23.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
24. 24.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) wire (b) battery (c) bulb (d) resistor
25. 25.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) False (b) True
26. 26.🔋 5 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)? =
27. 27.💡 An LED is joined to a 12 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
28. 28.💡 A red LED uses 2 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
29. 29.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) ammeter (b) wire (c) resistor (d) bulb
30. 30.What does the cloud server do? (a) shows data to you (b) stores data online (c) measures the real world (d) reads values, decides
31. 31.True or false: to measure classroom noise, use a sound sensor. (a) False (b) True
32. 32.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
33. 33.Which of these is a conductor? (a) a wooden stick (b) a paper strip (c) a rubber band (d) a brass key
34. 34.True or false: to stop a robot near walls, use a light sensor. (a) False (b) True
35. 35.🤖 Microcontroller or laptop: which one needs much more power? (a) laptop (b) microcontroller
36. 36.⏱️ How many milliseconds is a wait of 1.3 seconds?
37. 37.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    set pin 7 LOW
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
38. 38.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 1000 (c) 100 (d) 10
39. 39.🌈 A resistor has the colour bands red, orange, orange. What is its value (in ohms)?
40. 40.True or false: on an LED, the longer leg is the anode (+). (a) True (b) False

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