Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 461 · 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.🔺 An 8.8 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
2. 2.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 50 readings take?
3. 3.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
4. 4.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) switch the pump on/off (b) read the soil sensor (c) compare with the limit (d) wait a few seconds
5. 5.True or false: a long and a short line is the symbol for a resistor. (a) True (b) False
6. 6.🔍 Which is the odd one out? (a) a mixer grinder (b) a loudspeaker (c) an exhaust fan (d) a ceiling fan
7. 7.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 750 ms }
   How many milliseconds does one blink (ON + OFF) take?
8. 8.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) the board reads it (b) the sensor measures (c) the app shows it (d) it is sent by Wi-Fi
9. 9.🌈 A resistor has the colour bands grey, orange, yellow. What is its value in kilo-ohms (kΩ)? =
10. 10.🔋 How many 1.5 V cells must be joined in series to give 3 V?
11. 11.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 20 seconds?
12. 12.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
13. 13.💡 3 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =
14. 14.True or false: to use a cable with cuts is safe. (a) True (b) False
15. 15.Which drawing is the symbol for a wire? (a) a circle with A inside (b) a straight line (c) a small empty box (d) a line lifted at a gap
16. 16.True or false: to unplug idle chargers saves electricity. (a) True (b) False
17. 17.🔍 Which is the odd one out? (a) stop if a part gets hot (b) use small battery cells (c) use a cable with cuts (d) take cells out after use
18. 18.🔍 Which is the odd one out? (a) share only needed data (b) post your live location (c) set up with a parent (d) install software updates
19. 19.🔍 Which is the odd one out? (a) a plain table fan (b) a battery torch (c) a plain wall switch (d) a smart energy meter
20. 20.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the input (c) the battery (d) the process
21. 21.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) output (b) process (c) input
22. 22.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “switch the pump on/off”? (a) switch the pump on/off (b) compare with the limit
23. 23.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) process (b) input (c) output
24. 24.📏 How many amperes (A) is 1700 mA? =
25. 25.True or false: to touch a fallen wire is not safe. (a) False (b) True
26. 26.🔁 count = 2
    repeat 8 times { count = count + 10 }
    What is count at the end?
27. 27.🔐 Is it a good or a risky habit to reuse one password? (a) risky habit (b) good habit
28. 28.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) pauses for half a second (d) blinks 500 times
29. 29.True or false: a street light mainly gives out light. (a) True (b) False
30. 30.🔍 Which is the odd one out? (a) use a cable with cuts (b) climb an electric pole (c) open a phone charger (d) stay away from pylons
31. 31.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the widest gap (d) the one nearest an end
32. 32.🧮 A 4 V battery is joined to 4 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
33. 33.Which of these is a risky habit? (a) share camera links (b) change default passwords (c) cover unused cameras (d) read app permissions
34. 34.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 30 readings take?
35. 35.What does a fuse do? (a) blows if current is high (b) smooths a wobbly supply (c) makes a beeping sound (d) stores a little charge
36. 36.Which of these is true of a series circuit? (a) many paths for current (b) one out, the rest glow (c) used in house wiring (d) a single current path
37. 37.🔌 Is a woollen thread a conductor or an insulator? (a) an insulator (b) a conductor
38. 38.True or false: a paper strip is a conductor. (a) False (b) True
39. 39.What does the cloud server do? (a) acts on a command (b) reads values, decides (c) carries the data (d) stores data online
40. 40.Which of these is safe? (a) fly a kite near wires (b) throw cells in a fire (c) stop if a part gets hot (d) open a phone charger

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