Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 600 · 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 resistor colour code, which number does brown stand for?
2. 2.True or false: two or more cell symbols is the symbol for a battery. (a) False (b) True
3. 3.True or false: two or more cell symbols is the symbol for an ammeter. (a) False (b) True
4. 4.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) both A and B are true (d) only B is true
5. 5.⏱️ loop forever { LED ON; wait 700 ms; LED OFF; wait 1300 ms }
   How many times does the LED blink in 20 seconds?
6. 6.🤖 if (sound > 70) { red LED ON } else { green LED ON }
   The sound sensor reads 71. What happens? (a) green LED ON (b) red LED ON
7. 7.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) straight lines (c) dotted circles (d) little stars
8. 8.Which of these usually has a microcontroller inside? (a) a candle (b) a digital alarm clock (c) a bicycle bell (d) a spinning top
9. 9.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
10. 10.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) joins two wires (d) measures light
11. 11.Which of these is not an IoT device? (a) a fitness band with app (b) a Wi-Fi smart plug (c) a battery torch (d) a Wi-Fi weather station
12. 12.True or false: a circle with an X in it is the symbol for a wire. (a) True (b) False
13. 13.🧩 A capacitor in a circuit can … (a) spin a wheel (b) make light (c) measure heat (d) store charge briefly
14. 14.🔁 x = 1
    repeat 5 times { x = x × 2 }
    What is x at the end?
15. 15.What does a reed switch do? (a) flips up or down (b) closes near a magnet (c) springs back when let go (d) works only while pressed
16. 16.💡 A battery lights 2 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
17. 17.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
18. 18.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 360 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
19. 19.🔍 Which is the odd one out? (a) a light level reading (b) an LED lights up (c) a motion sensor signal (d) a button press
20. 20.⏱️ How many milliseconds is a wait of 3.6 seconds?
21. 21.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 45 °C. What is shown? (a) Warm (b) Cool (c) Hot
22. 22.⚠️ Someone is getting a shock and is still touching a wire. What should you do? (a) shout for an adult (b) pull them by the hand (c) wait and watch (d) pour water on them
23. 23.Which of these means the circuit is closed? (a) all wires are joined (b) a cell is taken out (c) the bulb is unscrewed (d) the switch is OFF
24. 24.🔍 Which is the odd one out? (a) leave fridge door open (b) iron one shirt at a time (c) run fans in empty rooms (d) set the AC to 24 °C
25. 25.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) neither part (d) the else part
26. 26.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 27 %. What happens? (a) pump OFF (b) pump ON
27. 27.True or false: an electric iron mainly gives out light. (a) True (b) False
28. 28.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
29. 29.True or false: to keep an incubator warm, use a temperature sensor. (a) False (b) True
30. 30.Which of these wastes electricity? (a) use daylight to read (b) switch off empty rooms (c) leave the TV on standby (d) set the AC to 24 °C
31. 31.🔺 A current of 50 mA flows when 11 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an oil lamp (d) an LED lamp
33. 33.🔍 Which is the odd one out? (a) a push button (b) a small display (c) a sound sensor (d) a keypad
34. 34.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) blinks 500 times (d) waits 500 seconds
35. 35.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
36. 36.True or false: the voltmeter measures current. (a) True (b) False
37. 37.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) it does not matter (d) both of them
38. 38.🔋 How many 3 V cells must be joined in series to give 9 V?
39. 39.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) True (b) False
40. 40.🧩 Which component smooths a wobbly supply? (a) thermistor (b) capacitor (c) motor (d) buzzer

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