Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 870 · 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.🔺 A current of 0.25 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
2. 2.🔺 A current of 1 A flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
3. 3.🔍 Which is the odd one out? (a) iron one shirt at a time (b) switch off empty rooms (c) close the fridge quickly (d) use LED lamps
4. 4.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) stay the same (d) zero
5. 5.🌈 A resistor has the colour bands red, orange, orange. What is its value (in ohms)?
6. 6.🔺 A 40 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
7. 7.🗺️ Before building a project, what should you write down first? (a) inputs and outputs (b) nothing at all (c) the box colour (d) the final price
8. 8.Which of these is safe? (a) use mains for a project (b) build with an adult near (c) poke things in a socket (d) touch a fallen wire
9. 9.🧩 Which component smooths a wobbly supply? (a) motor (b) thermistor (c) capacitor (d) LED
10. 10.⚡ A device works on 24 V and takes 2 A. What is its power (in watts)? =
11. 11.🧾 A family uses 190 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
12. 12.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
13. 13.True or false: “a single current path” is true of a series circuit. (a) True (b) False
14. 14.🔘 When a switch is ON, the circuit is … (a) open (b) cut (c) broken (d) closed
15. 15.⚡ A device works on 3 V and takes 1.5 A. What is its power (in watts)? =
16. 16.True or false: a rice cooker mainly gives out heat. (a) True (b) False
17. 17.True or false: to climb an electric pole is safe. (a) True (b) False
18. 18.🧩 Which component beeps for an alarm? (a) buzzer (b) resistor (c) fuse (d) diode
19. 19.🔺 A 22.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
20. 20.🧮 Three equal 75 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
21. 21.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 50 %. What happens? (a) pump OFF (b) pump ON
22. 22.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
23. 23.True or false: “a break stops every bulb” is true of a parallel circuit. (a) False (b) True
24. 24.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
25. 25.📶 A pin set LOW gives about … (a) 1.5 V (b) 0 V (c) 5 V (d) 9 V
26. 26.What does a reed switch do? (a) slides side to side (b) flips up or down (c) closes near a magnet (d) works only while pressed
27. 27.True or false: “each gets the full volts” is true of a parallel circuit. (a) True (b) False
28. 28.🔋 2 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
29. 29.🔺 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
30. 30.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
31. 31.True or false: a TV remote usually has a microcontroller inside. (a) False (b) True
32. 32.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V × I (d) P = V + I
33. 33.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) share it with friends (b) ask a parent first (c) post it online (d) type it all in
34. 34.⚙️ Which actuator would you use to show a status light? (a) a buzzer (b) a motor (c) an LED (d) a servo motor
35. 35.⚡ A device works on 1.5 V and takes 0.5 A. What is its power (in watts)? =
36. 36.What does the Wi-Fi link do? (a) carries the data (b) shows data to you (c) measures the real world (d) acts on a command
37. 37.Which of these gives us electricity? (a) an air conditioner (b) a washing machine (c) a cell (d) a computer
38. 38.🌐 Is a Wi-Fi weather station an IoT device? (a) not an IoT device (b) an IoT device
39. 39.⚡ What does a ceiling fan mainly change electricity into? (a) heat (b) sound (c) light (d) movement
40. 40.Which of these saves electricity? (a) leave the TV on standby (b) use LED lamps (c) use old filament bulbs (d) iron one shirt at a time

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