Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 592 · 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.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) turns the LED off (c) waits 500 seconds (d) pauses for half a second
2. 2.⏱️ repeat 3 times { buzzer ON; wait 700 ms; buzzer OFF; wait 700 ms }
   How many milliseconds does this take in all?
3. 3.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. How many bulbs glow?
4. 4.True or false: “a break stops every bulb” is true of a parallel circuit. (a) True (b) False
5. 5.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
6. 6.🔢 To plan an electronics project, which comes first: “list inputs and outputs” or “draw the circuit diagram”? (a) list inputs and outputs (b) draw the circuit diagram
7. 7.⏱️ How many milliseconds is a wait of 4.8 seconds?
8. 8.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
9. 9.Which of these is the process? (a) a button press (b) a motion sensor signal (c) a temperature reading (d) decide if soil is dry
10. 10.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
11. 11.🔺 A 0.8 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
12. 12.True or false: an electric iron mainly gives out heat. (a) False (b) True
13. 13.⏱️ repeat 5 times { buzzer ON; wait 500 ms; buzzer OFF; wait 300 ms }
    How many milliseconds does this take in all?
14. 14.Which of these is an insulator? (a) a rubber band (b) an iron nail (c) a brass key (d) a steel spoon
15. 15.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) run fans in empty rooms (d) switch off empty rooms
16. 16.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
17. 17.🔺 A current of 40 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
18. 18.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
19. 19.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
20. 20.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) never (c) when both are ON (d) when both are OFF
21. 21.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V + I (c) R = I ÷ V (d) R = V ÷ I
22. 22.Which drawing is the symbol for a bulb? (a) a circle with an X in it (b) a circle with M inside (c) two or more cell symbols (d) triangle, bar and arrows
23. 23.Which of these is a conductor? (a) a paper strip (b) a ceramic cup (c) a safety pin (d) a rubber band
24. 24.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
25. 25.📶 Digital or analog: a button: pressed or not? (a) digital (b) analog
26. 26.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
27. 27.🔢 To get a sensor reading onto a phone, what comes right after “it is sent by Wi-Fi”? (a) the board reads it (b) the sensor measures (c) the cloud stores it (d) the app shows it
28. 28.🔺 A current of 50 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
29. 29.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
30. 30.🔁 count = 3
    repeat 3 times { count = count + 9 }
    What is count at the end?
31. 31.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a resistor (d) a diode
32. 32.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
33. 33.🗺️ In an input → process → output plan, is “an LED lights up” the input, the process or the output? (a) output (b) input (c) process
34. 34.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) input (b) process (c) output
35. 35.🔺 A current of 10 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
36. 36.⚙️ Which actuator would you use to show a status light? (a) a servo motor (b) a buzzer (c) an LED (d) a motor
37. 37.💡 6 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?
38. 38.📏 How many watts (W) is 2.6 kW?
39. 39.🔁 count = 1
    while (count < 41) { count = count + 5 }
    How many times does the loop run?
40. 40.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?

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