Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 689 · 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.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V ÷ I (c) R = V + I (d) R = V × I
2. 2.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) a fuse (c) an input (d) an output
3. 3.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
4. 4.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
5. 5.🗺️ In an input → process → output plan, is “compare with a limit” the input, the process or the output? (a) process (b) input (c) output
6. 6.🔢 To run one loop of a plant-watering program, what comes right after “compare with the limit”? (a) wait a few seconds (b) read the soil sensor (c) switch the pump on/off
7. 7.True or false: a straight line is the symbol for a wire. (a) False (b) True
8. 8.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
9. 9.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
10. 10.Which of these means the circuit is closed? (a) the bulb is unscrewed (b) a wire has come loose (c) the loop is complete (d) the switch is OFF
11. 11.🔐 Is it a good or a risky habit to change default passwords? (a) risky habit (b) good habit
12. 12.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
13. 13.📏 In the water-pipe picture of a circuit, voltage is like … (a) the tap handle (b) the water tank lid (c) the pipe colour (d) the water pressure
14. 14.💡 An LED is joined to a 6 V battery through a 220 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) lights up (c) may burn out
15. 15.🔁 count = 4
    while (count < 25) { count = count + 3 }
    How many times does the loop run?
16. 16.🔺 A 3 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
17. 17.🔋 Does a cell give electricity or use electricity? (a) uses electricity (b) gives electricity
18. 18.🔘 Which kind of switch slides side to side? (a) a slide switch (b) a tilt switch (c) a push button (d) a toggle switch
19. 19.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the switch (b) the glass (c) the filament (d) the base
20. 20.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) False (b) True
21. 21.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 38 Ω resistor? (a) yellow-grey-black (b) orange-grey-black (c) orange-grey-brown (d) grey-orange-black
22. 22.🌈 A resistor has the colour bands white, yellow, brown. What is its value (in ohms)?
23. 23.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
24. 24.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.Which of these is not safe? (a) use small battery cells (b) take cells out after use (c) stop if a part gets hot (d) fly a kite near wires
26. 26.🧭 Which part of a microcontroller board shows the board is on? (a) the voltage regulator (b) the pins (c) the power LED (d) the main chip
27. 27.⚡ What does a ceiling fan mainly change electricity into? (a) heat (b) sound (c) movement (d) light
28. 28.🔍 Which is the odd one out? (a) a temperature sensor (b) a motor (c) an LED (d) a water pump
29. 29.Which drawing is the symbol for a wire? (a) a circle with M inside (b) a straight line (c) a circle with A inside (d) a plain rectangle
30. 30.⚡ Which formula gives electric power? (a) P = V × I (b) P = I ÷ V (c) P = V + I (d) P = V ÷ I
31. 31.📏 Which unit measures the push of a cell? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
32. 32.Which of these is not safe? (a) build with an adult near (b) touch a switch when wet (c) stop if a part gets hot (d) take cells out after use
33. 33.🔘 What does a switch do in a circuit? (a) makes electricity (b) stores current (c) changes the voltage (d) opens or closes the loop
34. 34.⚡ What does an exhaust fan mainly change electricity into? (a) movement (b) sound (c) light (d) heat
35. 35.💡 2 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
36. 36.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
37. 37.🧮 A 47 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
38. 38.True or false: to make a parking alarm, use a distance sensor. (a) True (b) False
39. 39.🌐 In an IoT system, which part measures the real world? (a) phone app (b) microcontroller (c) sensor (d) Wi-Fi
40. 40.True or false: many long-short pairs is the symbol for a battery. (a) True (b) False

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