Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 132 · 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.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
2. 2.Which of these is an insulator? (a) a safety pin (b) an iron nail (c) a copper wire (d) a rubber eraser
3. 3.🔍 Which is the odd one out? (a) leave fridge door open (b) use old filament bulbs (c) leave the TV on standby (d) use daylight to read
4. 4.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 640 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
5. 5.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 26 °C. What is shown? (a) Hot (b) Warm (c) Cool
6. 6.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
7. 7.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) False (b) True
8. 8.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an output (c) an input (d) a fuse
9. 9.Which of these usually has a microcontroller inside? (a) a hand pump (b) a spinning top (c) a plain wall switch (d) a smart watch
10. 10.💡 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)?
11. 11.🤖 Which is a safe power source for a beginner microcontroller board? (a) a 230 V cable (b) USB or a 9 V battery (c) a wall socket directly (d) bare mains wires
12. 12.🔍 Which sensor would you use to keep an incubator warm? (a) a light sensor (b) a soil moisture sensor (c) a temperature sensor (d) a motion sensor
13. 13.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
14. 14.True or false: to use a cable with cuts is not safe. (a) True (b) False
15. 15.Which of these is true of a series circuit? (a) one out, the rest glow (b) a break stops every bulb (c) each gets the full volts (d) used in house wiring
16. 16.Which of these is the process? (a) compare with a limit (b) the pump turns on (c) the fan starts (d) a soil moisture reading
17. 17.🔍 Which is the odd one out? (a) an LED lights up (b) a buzzer beeps (c) the pump turns on (d) a button press
18. 18.🌐 In an IoT system, which part shows data to you? (a) microcontroller (b) actuator (c) phone app (d) Wi-Fi
19. 19.📶 A pin that reads a push button is set as … (a) a resistor (b) an output (c) a battery (d) an input
20. 20.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
21. 21.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) the else part (d) neither part
22. 22.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
23. 23.Which drawing is the symbol for a resistor? (a) many long-short pairs (b) a long and a short line (c) a plain rectangle (d) a circle with an X in it
24. 24.🧮 Two resistors in parallel give a total that is … (a) their sum (b) always zero (c) less than either one (d) more than either one
25. 25.📶 A pin set LOW gives about … (a) 0 V (b) 9 V (c) 1.5 V (d) 5 V
26. 26.🔘 A bulb and a cell are joined through 3 switches on 3 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
27. 27.Which of these is not safe? (a) dry your hands first (b) fly kites in open fields (c) touch a switch when wet (d) stay away from pylons
28. 28.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) put it in the bathroom (b) tell it your passwords (c) mute it when not in use (d) let strangers use it
29. 29.🔌 Is a push button an input or an output for a microcontroller? (a) output (b) input
30. 30.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
31. 31.🔐 Is it a good or a risky habit to turn off unused gadgets? (a) good habit (b) risky habit
32. 32.What does the Wi-Fi link do? (a) stores data online (b) reads values, decides (c) measures the real world (d) carries the data
33. 33.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
34. 34.Which of these is a risky habit? (a) change default passwords (b) reuse one password (c) set a strong password (d) read app permissions
35. 35.🔁 count = 3
    repeat 10 times { count = count + 10 }
    What is count at the end?
36. 36.🔺 A current of 0.2 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.True or false: a plain rectangle is the symbol for a resistor. (a) True (b) False
38. 38.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. How many bulbs glow?
39. 39.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) ammeter (b) resistor (c) capacitor (d) battery
40. 40.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 7 seconds?

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