Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 513 · 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.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 90 readings take?
2. 2.⏱️ loop forever { LED ON; wait 850 ms; LED OFF; wait 450 ms }
   How many milliseconds does one blink (ON + OFF) take?
3. 3.✏️ In a circuit diagram, which part is drawn as a long and a short line? (a) cell (b) resistor (c) wire (d) junction
4. 4.Which drawing is the symbol for a bulb? (a) triangle against a bar (b) a circle with V inside (c) a plain rectangle (d) a circle with a cross
5. 5.⚡ A 12 W device works on 12 V. What current does it take (in amperes)? =
6. 6.⚠️ About how many volts do home sockets in India supply? (a) 9 V (b) 1.5 V (c) 12 V (d) 230 V
7. 7.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 2 hours?
8. 8.🌐 What does IoT stand for? (a) Input of Tools (b) Inside of Toys (c) Internet of Things (d) Internet of Talk
9. 9.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the bulb is unscrewed (d) the switch is ON
10. 10.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) unplug idle chargers (d) leave the TV on standby
11. 11.True or false: two or more cell symbols is the symbol for a battery. (a) False (b) True
12. 12.🔋 7 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
13. 13.🔍 Which sensor would you use to make a parking alarm? (a) a sound sensor (b) a soil moisture sensor (c) a distance sensor (d) a motion sensor
14. 14.🔐 Is it a good or a risky habit to ignore update messages? (a) risky habit (b) good habit
15. 15.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) stay the same (c) zero (d) smaller
16. 16.Which of these is an IoT device? (a) a wind-up clock (b) a Wi-Fi doorbell camera (c) a plain table fan (d) a plain wall switch
17. 17.Which of these mainly gives out heat? (a) a night lamp (b) a ceiling fan (c) a room heater (d) an electric drill
18. 18.🔋 3 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
19. 19.Which of these has no microcontroller inside? (a) a toy robot (b) a bicycle bell (c) a microwave oven (d) a washing machine
20. 20.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 28000 Ω resistor? (a) red-grey-red (b) grey-red-orange (c) red-grey-orange (d) red-grey-yellow
21. 21.🌐 A soil sensor sends a reading to an app every 30 minutes. How many readings arrive in 1 hour?
22. 22.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) both of them (c) it does not matter (d) none
23. 23.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 2 seconds?
24. 24.🔺 A current of 0.1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) input (b) process (c) output
26. 26.True or false: a tilt switch closes when tipped over. (a) False (b) True
27. 27.🧭 Which part of a microcontroller board restarts the program? (a) the voltage regulator (b) the reset button (c) the power LED (d) the USB port
28. 28.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) straight lines (c) little stars (d) dotted circles
29. 29.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) a smaller voltage (c) no voltage (d) the same voltage
30. 30.True or false: a reed switch closes near a magnet. (a) True (b) False
31. 31.Which of these usually has a microcontroller inside? (a) a spinning top (b) a candle (c) a washing machine (d) a wind-up toy
32. 32.🔁 x = 2
    repeat 1 time { x = x × 2 }
    What is x at the end?
33. 33.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are OFF (b) never (c) when either is ON (d) only when both are ON
34. 34.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
35. 35.Which drawing is the symbol for a capacitor? (a) two or more cell symbols (b) a circle with M inside (c) many long-short pairs (d) two equal parallel lines
36. 36.💡 Why is house wiring done in parallel? (a) so all go off together (b) to save copper only (c) each gets full voltage (d) to make bulbs dim
37. 37.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) share it with friends (b) ask a parent first (c) type it all in (d) post it online
38. 38.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
39. 39.🔍 Which is the odd one out? (a) a water heater (b) a table fan (c) a ceiling fan (d) an exhaust fan
40. 40.🔺 A 36 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =

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