Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 392 · 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.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
2. 2.🧭 Which part of a microcontroller board runs the program? (a) the power LED (b) the reset button (c) the main chip (d) the pins
3. 3.🔌 Is a steel coin a conductor or an insulator? (a) a conductor (b) an insulator
4. 4.🔺 A current of 1.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
5. 5.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they fix security holes (c) they change the colour (d) they delete the Wi-Fi
6. 6.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) stay the same (c) smaller (d) zero
7. 7.True or false: to start a fan when hot, use a temperature sensor. (a) True (b) False
8. 8.🔺 A current of 1 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 100 ms }
   How many times does the LED blink in 1 second?
10. 10.🔍 Which sensor would you use to switch on with a clap? (a) a temperature sensor (b) a distance sensor (c) a motion sensor (d) a sound sensor
11. 11.🔍 Which sensor would you use to measure classroom noise? (a) a sound sensor (b) a temperature sensor (c) a gas sensor (d) a light sensor
12. 12.True or false: to use daylight to read saves electricity. (a) True (b) False
13. 13.🔁 count = 0
    repeat 5 times { count = count + 10 }
    What is count at the end?
14. 14.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V × R (c) I = V ÷ R (d) I = V + R
15. 15.🔁 count = 9
    repeat 4 times { count = count + 6 }
    What is count at the end?
16. 16.Which of these is true of a series circuit? (a) bulbs share the voltage (b) each gets the full volts (c) many paths for current (d) one out, the rest glow
17. 17.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 17 %. What happens? (a) pump ON (b) pump OFF
18. 18.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 26 °C. What happens? (a) fan OFF (b) fan ON
19. 19.🔍 Which is the odd one out? (a) touch a switch when wet (b) use small battery cells (c) fly kites in open fields (d) build with an adult near
20. 20.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to an 8 V supply. What current flows (in mA)?
21. 21.Which job needs a temperature sensor? (a) measure classroom noise (b) switch on with a clap (c) keep an incubator warm (d) make a parking alarm
22. 22.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 900 ms }
    How many times does the LED blink in 1 second?
23. 23.Which of these has no microcontroller inside? (a) a digital thermometer (b) a hand pump (c) a TV remote (d) a toy robot
24. 24.🔁 repeat 4 times { repeat 5 times { beep } }
    How many beeps are there?
25. 25.What does a toggle switch do? (a) closes near a magnet (b) flips up or down (c) springs back when let go (d) closes when tipped over
26. 26.🔍 Which is the odd one out? (a) a buzzer (b) a loudspeaker (c) a doorbell (d) an LED lamp
27. 27.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
28. 28.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
29. 29.🔍 An object is 272 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
30. 30.Which of these usually has a microcontroller inside? (a) a hand pump (b) a candle (c) a washing machine (d) a spinning top
31. 31.What does an LDR do? (a) is a resistance knob (b) stores a little charge (c) senses how bright it is (d) limits the current
32. 32.True or false: a push button closes when tipped over. (a) True (b) False
33. 33.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) good habit (b) risky habit
34. 34.🔐 Privacy for a smart device means controlling … (a) its battery size (b) who can see your data (c) its colour (d) how loud it beeps
35. 35.🔘 A cell and a bulb are joined to 3 side-by-side paths with one switch on each path — A, B and C (parallel). A is ON, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
36. 36.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
37. 37.🧮 Resistors of 50 Ω, 330 Ω, 47 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
38. 38.🔁 x = 3
    repeat 1 time { x = x × 2 }
    What is x at the end?
39. 39.True or false: “a single current path” is true of a parallel circuit. (a) True (b) False
40. 40.📶 Digital or analog: the room temperature? (a) digital (b) analog

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