Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 728 · 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.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) only when both are OFF (b) never (c) when either is ON (d) only when both are ON
2. 2.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 14 °C. What is shown? (a) Hot (b) Cool (c) Warm
3. 3.⚡ What does a street light mainly change electricity into? (a) heat (b) movement (c) light (d) sound
4. 4.🧩 Which component lets current go one way? (a) diode (b) capacitor (c) LED (d) thermistor
5. 5.🧩 Which component boosts a small signal? (a) diode (b) capacitor (c) thermistor (d) transistor
6. 6.🔁 total = 0
   for i = 1 to 4 { total = total + i }
   What is total at the end?
7. 7.💡 A battery lights 3 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
8. 8.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a steel coin. Does the bulb glow? (a) Yes (b) No
9. 9.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
10. 10.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) each gets full voltage (c) so all go off together (d) to save copper only
11. 11.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a resistor (d) a buzzer
12. 12.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they delete the Wi-Fi (c) they change the colour (d) they fix security holes
13. 13.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
14. 14.Which of these is a risky habit? (a) cover unused cameras (b) set a strong password (c) read app permissions (d) accept every permission
15. 15.🔁 count = 4
    while (count < 18) { count = count + 2 }
    How many times does the loop run?
16. 16.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 10 seconds?
17. 17.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) output (b) input (c) process
18. 18.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
19. 19.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 4.25 V supply. What current flows (in mA)?
20. 20.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) measure heat (d) spin a wheel
21. 21.🔍 Which is the odd one out? (a) leave the TV on standby (b) unplug idle chargers (c) set the AC to 24 °C (d) use daylight to read
22. 22.Which of these is the input? (a) a buzzer beeps (b) count button presses (c) a temperature reading (d) check if temp > 30
23. 23.Which of these mainly gives out light? (a) an electric iron (b) an electric kettle (c) a tube light (d) a table fan
24. 24.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only B is true (c) both are false (d) only A is true
25. 25.Which of these uses electricity? (a) a cell (b) a computer (c) a wind turbine (d) a battery
26. 26.True or false: the ammeter is joined in series. (a) True (b) False
27. 27.💡 A red LED uses 2 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
28. 28.True or false: “compare with a limit” is the process. (a) True (b) False
29. 29.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) waits 500 seconds (d) blinks 500 times
30. 30.🔍 Which is the odd one out? (a) an LED lamp (b) a tube light (c) a table fan (d) a traffic signal
31. 31.True or false: a microcontroller has a built-in keyboard. (a) True (b) False
32. 32.Which drawing is the symbol for a battery? (a) one tall, one short bar (b) a straight line (c) two or more cell symbols (d) a circle with V inside
33. 33.🔺 A 4.7 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
34. 34.🔋 How many 1.5 V cells must be joined in series to give 6 V?
35. 35.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 50 % (c) 5 % (d) 0 %
36. 36.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
37. 37.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the glass (c) the switch (d) the filament
38. 38.💡 In a series circuit, how many paths does the current have? (a) two (b) one for each bulb (c) none (d) one
39. 39.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 4 seconds?
40. 40.🔋 3 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =

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