Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 582 · 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.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 550 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
2. 2.🔘 Which kind of switch springs back when let go? (a) a reed switch (b) a tilt switch (c) a toggle switch (d) a push button
3. 3.⚠️ Which power source should children use for electronics projects? (a) a small battery pack (b) a wall socket (c) an inverter socket (d) a mains extension board
4. 4.⏱️ A program says “wait 6000 ms”. How many seconds is that? =
5. 5.📏 How many amperes (A) is 150 mA? =
6. 6.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a woollen thread across the gap. Does the bulb glow? (a) Yes (b) No
7. 7.💡 Why does an LED need a resistor in series? (a) to store charge (b) to make it brighter (c) to limit the current (d) to change its colour
8. 8.Which of these is a conductor? (a) a paper strip (b) a brass key (c) a ceramic cup (d) a dry cork
9. 9.🔁 x = 3
   repeat 2 times { x = x × 2 }
   What is x at the end?
10. 10.What does the actuator do? (a) acts on a command (b) carries the data (c) reads values, decides (d) shows data to you
11. 11.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
    The temperature is 20 °C. What is shown? (a) Warm (b) Cool (c) Hot
12. 12.⏱️ repeat 6 times { buzzer ON; wait 400 ms; buzzer OFF; wait 700 ms }
    How many milliseconds does this take in all?
13. 13.🔐 Privacy for a smart device means controlling … (a) its colour (b) its battery size (c) who can see your data (d) how loud it beeps
14. 14.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
15. 15.🔺 An 8 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
16. 16.Which of these gives us electricity? (a) an air conditioner (b) a washing machine (c) a water pump (d) a bicycle dynamo
17. 17.True or false: on a cell, “the flat end” means the − (negative) end. (a) False (b) True
18. 18.🔍 Which is the odd one out? (a) a brass key (b) a cotton thread (c) a paper strip (d) a wooden stick
19. 19.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 91 Ω resistor? (a) white-brown-brown (b) brown-brown-black (c) white-brown-black (d) brown-white-black
20. 20.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
21. 21.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 5 is taken out of its holder. Does bulb 2 glow? (a) Yes (b) No
22. 22.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) pull them by the hand (b) shout for an adult (c) pour water on them (d) wait and watch
23. 23.📏 How many amperes (A) is 590 mA? =
24. 24.🧩 Which part changes electrical energy into movement? (a) a fuse (b) an LED (c) a resistor (d) a motor
25. 25.🔺 A current of 0.2 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
26. 26.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a safety pin. Does the bulb glow? (a) Yes (b) No
27. 27.True or false: a reed switch stays where you flip it. (a) False (b) True
28. 28.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
29. 29.🔍 Which sensor would you use to start a fan when hot? (a) a soil moisture sensor (b) a temperature sensor (c) a light sensor (d) a motion sensor
30. 30.🔺 A current of 2.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
31. 31.True or false: “how loud a sound is” is an analog signal. (a) True (b) False
32. 32.True or false: “a temperature reading” is the input. (a) True (b) False
33. 33.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) when both are ON (c) when both are OFF (d) never
34. 34.🔺 A current of 20 mA flows when 9.4 V is joined across a resistor. What is its resistance (in ohms)?
35. 35.Which of these is a good habit? (a) reuse one password (b) post your live location (c) ignore update messages (d) read app permissions
36. 36.🔦 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 a wooden stick. Does the bulb glow? (a) No (b) Yes
37. 37.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 3 glow? (a) No (b) Yes
38. 38.🌈 A resistor has the colour bands brown, yellow, black. What is its value (in ohms)?
39. 39.🔁 What does a variable do in a program? (a) stores a value (b) measures light (c) blinks an LED (d) joins two wires
40. 40.🔁 count = 8
    repeat 4 times { count = count + 2 }
    What is count at the end?

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