Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 81 · 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.True or false: if the loop is complete, the circuit is closed and current flows. (a) False (b) True
2. 2.🔍 Which is the odd one out? (a) a ceramic cup (b) a rubber eraser (c) an iron nail (d) a cotton thread
3. 3.🌈 Which band is read first on a resistor? (a) any band (b) the one nearest an end (c) the widest gap (d) the gold band
4. 4.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
5. 5.Which of these is not an IoT device? (a) a Wi-Fi doorbell camera (b) a pencil sharpener (c) a Wi-Fi weather station (d) an app-controlled bulb
6. 6.⏱️ loop forever { LED ON; wait 1600 ms; LED OFF; wait 400 ms }
   How many times does the LED blink in 8 seconds?
7. 7.🔁 count = 9
   repeat 10 times { count = count + 3 }
   What is count at the end?
8. 8.🔺 A current of 50 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.Which of these means the circuit is closed? (a) a wire is cut (b) the bulb is unscrewed (c) a wire has come loose (d) all wires are joined
10. 10.🔺 A 1.5 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
11. 11.🔁 count = 9
    repeat 10 times { count = count + 4 }
    What is count at the end?
12. 12.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 426. What happens? (a) lamp ON (b) lamp OFF
13. 13.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) it does not matter (c) none (d) both of them
15. 15.True or false: “a tilt switch: on or off” is an analog signal. (a) False (b) True
16. 16.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) the same voltage (c) double the voltage (d) half the voltage
17. 17.🔁 x = 5
    repeat 2 times { x = x × 2 }
    What is x at the end?
18. 18.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 60 (c) 10 (d) 1000
19. 19.💡 6 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 1 and 2 are taken out of their holders. Does bulb 6 glow? (a) No (b) Yes
20. 20.🌈 In the resistor colour code, which number does white stand for?
21. 21.🔍 Which is the odd one out? (a) iron one shirt at a time (b) set the AC to 24 °C (c) run fans in empty rooms (d) leave fridge door open
22. 22.✏️ In a circuit diagram, which part is drawn as a circle with A inside? (a) ammeter (b) diode (c) voltmeter (d) bulb
23. 23.🧮 Resistors of 150 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
24. 24.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
25. 25.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) compare with the limit (b) wait a few seconds (c) switch the pump on/off
26. 26.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
27. 27.⚡ A 24 W device works on 12 V. What current does it take (in amperes)? =
28. 28.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
29. 29.🔁 repeat 5 times { repeat 5 times { beep } }
    How many beeps are there?
30. 30.🔁 count = 2
    repeat 2 times { count = count + 9 }
    What is count at the end?
31. 31.🤖 How does a new program get onto a microcontroller board? (a) drawn with a pen (b) typed on the chip (c) uploaded over USB (d) sent by sound
32. 32.🔋 How many 1.2 V cells must be joined in series to give 2.4 V?
33. 33.🔗 Series or parallel circuit: “many paths for current”? (a) series (b) parallel
34. 34.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) wind energy (c) nuclear energy (d) electrical energy
35. 35.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
36. 36.✏️ In a circuit diagram, which part is drawn as triangle, bar and arrows? (a) diode (b) motor (c) LED (d) cell
37. 37.✏️ In a circuit diagram, which part is drawn as a circle with a cross? (a) bulb (b) capacitor (c) diode (d) cell
38. 38.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 230 V (c) 0.5 V (d) 1.5 V
39. 39.🔺 A 15 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
40. 40.🔺 A current of 2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =

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