Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 116 · 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.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 42000 Ω resistor? (a) yellow-red-yellow (b) yellow-red-red (c) yellow-red-orange (d) red-yellow-orange
2. 2.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire has come loose (d) all wires are joined
3. 3.Which of these is safe? (a) poke things in a socket (b) touch a switch when wet (c) take cells out after use (d) open a phone charger
4. 4.True or false: a microcontroller has a built-in keyboard. (a) False (b) True
5. 5.Which of these is a risky habit? (a) tap unknown app links (b) log out of shared phones (c) cover unused cameras (d) change default passwords
6. 6.⚡ A device works on 9 V and takes 0.5 A. What is its power (in watts)? =
7. 7.🗺️ In an input → process → output plan, is “a temperature reading” the input, the process or the output? (a) input (b) process (c) output
8. 8.💡 What happens if an LED is put in backwards? (a) it changes colour (b) it lights brighter (c) it does not light (d) it makes a sound
9. 9.True or false: to fly a kite near wires is not safe. (a) False (b) True
10. 10.True or false: a washing machine usually has a microcontroller inside. (a) False (b) True
11. 11.Which of these means the circuit is open? (a) the loop is complete (b) all wires are joined (c) the switch is OFF (d) the switch is ON
12. 12.🔗 Series or parallel circuit: “many paths for current”? (a) series (b) parallel
13. 13.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
14. 14.🧮 A 470 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
15. 15.🧭 Which part of a microcontroller board runs the program? (a) the voltage regulator (b) the main chip (c) the USB port (d) the reset button
16. 16.🤖 if (temperature > 38) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 16 °C. What is shown? (a) Warm (b) Hot (c) Cool
17. 17.🔗 Series or parallel circuit: “own switch for each bulb”? (a) series (b) parallel
18. 18.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) both parts (c) neither part (d) the else part
19. 19.🔢 To plan an electronics project, which comes first: “test it and fix it” or “build it with an adult”? (a) test it and fix it (b) build it with an adult
20. 20.🔺 A current of 20 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
21. 21.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
22. 22.🧮 Resistors of 10 Ω, 33 Ω, 47 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
23. 23.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) so all go off together (c) to save copper only (d) each gets full voltage
24. 24.💡 4 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?
25. 25.🔍 Which is the odd one out? (a) a steel coin (b) a cotton thread (c) a brass key (d) a safety pin
26. 26.Which of these uses electricity? (a) a generator (b) a computer (c) a cell (d) a power station
27. 27.🧮 A 100 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
28. 28.Which of these mainly makes sound? (a) an electric drill (b) an electric toy car (c) a siren (d) a night lamp
29. 29.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 500 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
30. 30.🔺 A current of 2 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
32. 32.💡 4 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =
33. 33.🔢 To run one loop of a plant-watering program, what comes right after “read the soil sensor”? (a) compare with the limit (b) switch the pump on/off (c) wait a few seconds
34. 34.True or false: a mixer grinder mainly gives out light. (a) False (b) True
35. 35.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) a bigger voltage (c) no voltage (d) a smaller voltage
36. 36.🔺 A current of 1.5 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
37. 37.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
38. 38.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V ÷ R (c) I = V × R (d) I = V + R
39. 39.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) the switch is OFF (d) a wire has come loose
40. 40.⚡ An 18 W device works on 6 V. What current does it take (in amperes)? =

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