Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 747 · 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.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the else part (c) both parts (d) the if part
2. 2.💡 4 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 4 glow? (a) No (b) Yes
3. 3.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 LOW
   set pin 8 HIGH
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
4. 4.🔺 A current of 0.2 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
5. 5.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
6. 6.Which drawing is the symbol for a battery? (a) one tall, one short bar (b) two or more cell symbols (c) a circle with M inside (d) a circle with an X in it
7. 7.🧩 Which component stores a little charge? (a) buzzer (b) thermistor (c) capacitor (d) fuse
8. 8.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) not joined (c) by Wi-Fi (d) in series
9. 9.📏 Which unit measures energy used each second? (a) ohm (Ω) (b) ampere (A) (c) watt (W) (d) volt (V)
10. 10.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
11. 11.What does a reed switch do? (a) flips up or down (b) springs back when let go (c) slides side to side (d) closes near a magnet
12. 12.🔺 A current of 2.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🔁 count = 8
    repeat 6 times { count = count + 3 }
    What is count at the end?
14. 14.⏱️ A program says “wait 4750 ms”. How many seconds is that? =
15. 15.True or false: “used in house wiring” is true of a series circuit. (a) True (b) False
16. 16.⚙️ Which actuator would you use to open a gate to 90°? (a) a display (b) a pump (c) a servo motor (d) an LED
17. 17.True or false: “a single current path” is true of a series circuit. (a) False (b) True
18. 18.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the metal tip (c) the bare end (d) the plastic handle
19. 19.⚡ What does an LED lamp mainly change electricity into? (a) heat (b) movement (c) light (d) sound
20. 20.📏 How many watts (W) is 3.7 kW?
21. 21.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) smaller (d) zero
22. 22.🧩 A capacitor in a circuit can … (a) store charge briefly (b) spin a wheel (c) make light (d) measure heat
23. 23.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the glass (b) the filament (c) the base (d) the switch
24. 24.💡 An LED is joined to a 6 V battery through a 1000 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) may burn out (b) lights up (c) does not light
25. 25.🔍 Which is the odd one out? (a) a motion sensor signal (b) a button press (c) a buzzer beeps (d) a soil moisture reading
26. 26.What does a slide switch do? (a) stays where you flip it (b) closes when tipped over (c) slides side to side (d) flips up or down
27. 27.🔺 A current of 20 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
28. 28.🔌 Is a motor an input or an output for a microcontroller? (a) input (b) output
29. 29.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) bulb (b) diode (c) junction (d) switch
30. 30.💡 2 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. Does bulb 1 glow? (a) Yes (b) No
31. 31.💡 An LED is joined to a 9 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) may burn out (c) lights up
32. 32.Which job is done by the USB port? (a) runs the program (b) keeps the voltage steady (c) shows the board is on (d) brings power and code
33. 33.🔋 Cells joined + to − in a row (series) give … (a) no voltage (b) the same voltage (c) a smaller voltage (d) a bigger voltage
34. 34.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
35. 35.🧮 Resistors of 22 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
36. 36.🧩 Which component makes things spin? (a) fuse (b) LED (c) transistor (d) motor
37. 37.💡 5 identical bulbs are joined in series with a 15 V battery (ideal wires). How many volts does each bulb get? =
38. 38.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they explode (c) they keep glowing (d) they all go out
39. 39.🔍 Which sensor would you use to water a dry plant? (a) a rain sensor (b) a soil moisture sensor (c) a distance sensor (d) a sound sensor
40. 40.True or false: a ceramic cup is an insulator. (a) True (b) False

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