Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 185 · 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 the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V ÷ R (c) I = R ÷ V (d) I = V + R
2. 2.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 230 Ω resistor? (a) orange-red-brown (b) red-orange-red (c) red-orange-brown (d) red-orange-black
3. 3.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 6 hours?
4. 4.True or false: resistance is measured in amperes (A). (a) True (b) False
5. 5.🔍 Which is the odd one out? (a) a sound sensor (b) a small display (c) a motion sensor (d) a light sensor
6. 6.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 590 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
7. 7.🔌 Is a steel spoon a conductor or an insulator? (a) an insulator (b) a conductor
8. 8.True or false: a plastic straw is a conductor. (a) True (b) False
9. 9.Which of these mainly makes movement? (a) a room heater (b) an electric kettle (c) a table fan (d) a rice cooker
10. 10.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) smaller (c) zero (d) stay the same
11. 11.🌐 How does a home IoT device usually send its data to the app? (a) over Wi-Fi (b) through a candle (c) by post (d) by shouting
12. 12.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) adds 1 to count (d) prints 1
13. 13.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
14. 14.True or false: “a single current path” is true of a series circuit. (a) False (b) True
15. 15.🔍 Which is the odd one out? (a) poke things in a socket (b) use a cable with cuts (c) open a phone charger (d) keep drinks far away
16. 16.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V × I (d) P = V + I
17. 17.Which of these wastes electricity? (a) use old filament bulbs (b) use LED lamps (c) unplug idle chargers (d) use daylight to read
18. 18.🧮 A 3.2 V battery is joined to 10 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
19. 19.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
20. 20.🧮 Resistors of 100 Ω and 50 Ω are joined in series. What is the total resistance (in ohms)?
21. 21.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
22. 22.💡 An LED is joined to a 5 V battery through a 330 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) lights up (c) may burn out
23. 23.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 250 ms }
    How many times does the LED blink in 16 seconds?
24. 24.🔁 x = 2
    repeat 5 times { x = x × 2 }
    What is x at the end?
25. 25.Which of these is the input? (a) compare with a limit (b) a button press (c) count button presses (d) decide if soil is dry
26. 26.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
27. 27.🔘 Which kind of switch stays where you flip it? (a) a toggle switch (b) a reed switch (c) a slide switch (d) a push button
28. 28.🔺 A current of 1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
29. 29.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
30. 30.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “build it with an adult”? (a) build it with an adult (b) pick a problem to solve
31. 31.🔺 A current of 0.2 A flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.🗺️ In an input → process → output plan, is “a button press” the input, the process or the output? (a) process (b) output (c) input
33. 33.🔗 Series or parallel circuit: “a single current path”? (a) series (b) parallel
34. 34.📶 A pin set LOW gives about … (a) 9 V (b) 0 V (c) 1.5 V (d) 5 V
35. 35.True or false: if the loop is complete, the circuit is open and no current flows. (a) True (b) False
36. 36.🔋 A 6 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
37. 37.🧩 Which component smooths a wobbly supply? (a) transistor (b) capacitor (c) fuse (d) LED
38. 38.💡 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)?
39. 39.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) spin a wheel (d) measure heat
40. 40.🔐 Is it a good or a risky habit to ignore update messages? (a) risky habit (b) good habit

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids