Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 192 · 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 an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
2. 2.⏱️ repeat 4 times { buzzer ON; wait 800 ms; buzzer OFF; wait 100 ms }
   How many milliseconds does this take in all?
3. 3.🌈 A resistor has the colour bands red, black, orange. What is its value (in ohms)?
4. 4.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a motor (c) a fuse (d) an LED
5. 5.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
6. 6.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
7. 7.True or false: “check if temp > 30” is the process. (a) False (b) True
8. 8.Which of these saves electricity? (a) set the AC to 24 °C (b) iron one shirt at a time (c) use old filament bulbs (d) run fans in empty rooms
9. 9.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 210 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
10. 10.🌈 A resistor has the colour bands orange, orange, orange. What is its value in kilo-ohms (kΩ)? =
11. 11.True or false: a slide switch flips up or down. (a) False (b) True
12. 12.🔐 Privacy for a smart device means controlling … (a) how loud it beeps (b) who can see your data (c) its battery size (d) its colour
13. 13.Which of these is safe? (a) dry your hands first (b) climb an electric pole (c) open a phone charger (d) use mains for a project
14. 14.⚡ What does a tube light mainly change electricity into? (a) movement (b) light (c) heat (d) sound
15. 15.🌈 A resistor has the colour bands red, brown, orange. What is its value in kilo-ohms (kΩ)? =
16. 16.🧮 A 2.75 V battery is joined to 5 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
17. 17.📏 In the water-pipe picture of a circuit, voltage is like … (a) the tap handle (b) the pipe colour (c) the water tank lid (d) the water pressure
18. 18.True or false: to unplug idle chargers saves electricity. (a) True (b) False
19. 19.True or false: on a cell, “the end with a bump” means the − (negative) end. (a) False (b) True
20. 20.🌈 A resistor has the colour bands green, white, brown. What is its value (in ohms)?
21. 21.True or false: “many paths for current” is true of a parallel circuit. (a) False (b) True
22. 22.Which of these is true of a series circuit? (a) each gets the full volts (b) one out, the rest glow (c) a single current path (d) used in house wiring
23. 23.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) smaller (d) bigger
24. 24.🔌 Is a woollen thread a conductor or an insulator? (a) a conductor (b) an insulator
25. 25.🔘 What does a switch do in a circuit? (a) opens or closes the loop (b) makes electricity (c) changes the voltage (d) stores current
26. 26.📏 How many ohms (Ω) is 1.1 kΩ?
27. 27.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) the sensor measures (b) it is sent by Wi-Fi (c) the board reads it (d) the app shows it
28. 28.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
29. 29.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 18 °C. What is shown? (a) Hot (b) Warm (c) Cool
30. 30.🔘 A bulb and a cell are joined through 6 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
31. 31.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
32. 32.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
    The temperature is 33 °C. What is shown? (a) Warm (b) Hot (c) Cool
33. 33.True or false: a rice cooker mainly gives out heat. (a) False (b) True
34. 34.Which of these is a conductor? (a) a metal paper clip (b) a ceramic cup (c) a paper strip (d) a cotton thread
35. 35.🔌 Which metal is used for most electric wires at home? (a) glass (b) plastic (c) rubber (d) copper
36. 36.What does a resistor do? (a) turns a fan or wheels (b) blows if current is high (c) boosts a small signal (d) has coloured bands
37. 37.True or false: on a cell, “the flat end” means the + (positive) end. (a) True (b) False
38. 38.🗺️ Before building a project, what should you write down first? (a) the final price (b) inputs and outputs (c) nothing at all (d) the box colour
39. 39.True or false: a circle with a cross is the symbol for a bulb. (a) False (b) True
40. 40.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?

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