Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 190 · 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: a bicycle bell has no microcontroller inside. (a) True (b) False
2. 2.True or false: to use small battery cells is safe. (a) False (b) True
3. 3.🧮 A 330 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
4. 4.Which job needs an LED? (a) spin a robot’s wheels (b) show a status light (c) open a gate to 90° (d) show the temperature
5. 5.🔍 Which is the odd one out? (a) a steel spoon (b) a metal paper clip (c) a copper wire (d) a glass marble
6. 6.🔁 total = 0
   for i = 1 to 10 { total = total + i }
   What is total at the end?
7. 7.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) dotted circles (d) wavy lines
8. 8.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
9. 9.💡 3 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
10. 10.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they keep glowing (b) they get dimmer (c) they explode (d) they all go out
11. 11.⚡ A 4.5 W device works on 9 V. What current does it take (in amperes)? =
12. 12.Which of these mainly gives out heat? (a) a loudspeaker (b) an electric toy car (c) an electric kettle (d) an electric drill
13. 13.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
14. 14.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
15. 15.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
16. 16.💡 2 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
17. 17.Which of these is the process? (a) a motion sensor signal (b) an alert on the phone (c) count button presses (d) the fan starts
18. 18.What does a push button do? (a) works only while pressed (b) stays where you flip it (c) closes when tipped over (d) closes near a magnet
19. 19.🌈 A resistor has the colour bands green, white, yellow. What is its value in kilo-ohms (kΩ)? =
20. 20.🔍 Which sensor would you use to keep an incubator warm? (a) a gas sensor (b) a distance sensor (c) a temperature sensor (d) a light sensor
21. 21.Which of these has no microcontroller inside? (a) a toy robot (b) a TV remote (c) a hand pump (d) a digital alarm clock
22. 22.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 60 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
23. 23.🔺 A 2.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
24. 24.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
25. 25.Which of these is the output? (a) an alert on the phone (b) compare with a limit (c) a light level reading (d) a button press
26. 26.True or false: “an LED lights up” is the input. (a) True (b) False
27. 27.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to store charge (c) to change its colour (d) to make it brighter
28. 28.🔍 Which is the odd one out? (a) share the Wi-Fi key (b) log out of shared phones (c) accept every permission (d) ignore update messages
29. 29.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is OFF and D is OFF. Does the bulb glow? (a) Yes (b) No
30. 30.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 100 (c) 1000 (d) 10
31. 31.🔢 To plan an electronics project, which is the FIRST step? (a) build it with an adult (b) pick a problem to solve (c) test it and fix it (d) list inputs and outputs
32. 32.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
33. 33.🌈 A resistor has the colour bands red, green, red. What is its value (in ohms)?
34. 34.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
35. 35.Which drawing is the symbol for a junction? (a) a circle with an X in it (b) a line lifted at a gap (c) triangle, bar and arrows (d) a dot where wires meet
36. 36.🔋 Does a refrigerator give electricity or use electricity? (a) gives electricity (b) uses electricity
37. 37.🔌 Is a speaker an input or an output for a microcontroller? (a) input (b) output
38. 38.🤖 “if (A AND B)” is true when … (a) only B is true (b) both A and B are true (c) only A is true (d) both are false
39. 39.Which drawing is the symbol for a capacitor? (a) a line lifted at a gap (b) triangle against a bar (c) a circle with an X in it (d) two equal parallel lines
40. 40.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a cotton thread across the gap. Does the bulb glow? (a) Yes (b) No

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