Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 163 · 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.💡 What does LED stand for? (a) light energy dial (b) light-emitting diode (c) low energy device (d) large electric dial
2. 2.📏 How many ohms (Ω) is 4 kΩ?
3. 3.True or false: to use small battery cells is safe. (a) False (b) True
4. 4.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I ÷ R (c) V = I × R (d) V = I + R
5. 5.🔍 Which is the odd one out? (a) leave the TV on standby (b) switch off empty rooms (c) leave fridge door open (d) use old filament bulbs
6. 6.📏 Which unit measures how much a part resists? (a) ohm (Ω) (b) volt (V) (c) watt (W) (d) ampere (A)
7. 7.🔺 A 2.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
8. 8.True or false: a tube light mainly gives out light. (a) True (b) False
9. 9.🌐 Is a plain table fan an IoT device? (a) an IoT device (b) not an IoT device
10. 10.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) stay the same (c) bigger (d) smaller
11. 11.Which job is done by the pins? (a) restarts the program (b) brings power and code (c) connect sensors and LEDs (d) keeps the voltage steady
12. 12.True or false: the voltmeter is joined across a part. (a) False (b) True
13. 13.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
14. 14.🤖 if (sound > 60) { red LED ON } else { green LED ON }
    The sound sensor reads 65. What happens? (a) green LED ON (b) red LED ON
15. 15.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) Yes (b) No
16. 16.🌐 Is an app-controlled bulb an IoT device? (a) not an IoT device (b) an IoT device
17. 17.🔍 Which is the odd one out? (a) cover unused cameras (b) set up with a parent (c) accept every permission (d) install software updates
18. 18.🔺 A 9.4 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
19. 19.Which of these is not safe? (a) use small battery cells (b) stop if a part gets hot (c) take cells out after use (d) throw cells in a fire
20. 20.Which of these is an insulator? (a) an iron nail (b) a cotton thread (c) a copper wire (d) a brass key
21. 21.🌈 A resistor has the colour bands orange, blue, orange. What is its value (in ohms)?
22. 22.🌐 Each reading a sensor sends is 50 bytes. How many bytes do 80 readings take?
23. 23.🔋 Does a battery give electricity or use electricity? (a) gives electricity (b) uses electricity
24. 24.Which of these is a conductor? (a) a steel coin (b) a wooden stick (c) a woollen thread (d) a ceramic cup
25. 25.📶 On a 5 V board, a pin set HIGH gives about … (a) 50 V (b) 5 V (c) 230 V (d) 0 V
26. 26.💡 4 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
27. 27.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 21 °C. What happens? (a) fan ON (b) fan OFF
28. 28.🌈 In the resistor colour code, which number does blue stand for?
29. 29.What does a buzzer do? (a) blows if current is high (b) beeps for an alarm (c) senses how hot it is (d) boosts a small signal
30. 30.🔋 6 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
31. 31.🔁 repeat 4 times { repeat 2 times { beep } }
    How many beeps are there?
32. 32.🔌 Most metals are good … (a) insulators (b) batteries (c) conductors (d) magnets only
33. 33.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
34. 34.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2000 Ω resistor? (a) red-black-orange (b) red-black-brown (c) orange-red-red (d) red-black-red
35. 35.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V × I (d) P = V + I
36. 36.🔢 To run one loop of a plant-watering program, which is the LAST step? (a) switch the pump on/off (b) compare with the limit (c) wait a few seconds (d) read the soil sensor
37. 37.True or false: to keep an incubator warm, use a soil moisture sensor. (a) True (b) False
38. 38.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 310 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
39. 39.📶 A pin set LOW gives about … (a) 0 V (b) 9 V (c) 1.5 V (d) 5 V
40. 40.📏 How many milliamperes (mA) is 2.63 A?

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