Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 678 · 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 part of a microcontroller board brings power and code? (a) the power LED (b) the main chip (c) the pins (d) the USB port
2. 2.🔺 A current of 0.1 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
3. 3.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a resistor (c) a diode (d) a buzzer
4. 4.📶 Digital or analog: a knob turned part way? (a) digital (b) analog
5. 5.🔺 A current of 20 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
6. 6.💡 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) ON (b) OFF
7. 7.💡 2 identical bulbs are joined in series with a 2 V battery (ideal wires). How many volts does each bulb get? =
8. 8.🔗 Series or parallel circuit: “each gets the full volts”? (a) parallel (b) series
9. 9.True or false: “each gets the full volts” is true of a series circuit. (a) False (b) True
10. 10.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 2.5 V supply. What current flows (in mA)?
11. 11.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 85. What happens? (a) green LED ON (b) red LED ON
12. 12.🔋 6 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)? =
13. 13.🔍 Which is the odd one out? (a) a glass marble (b) aluminium foil (c) a copper wire (d) a steel spoon
14. 14.Which of these is an insulator? (a) a copper wire (b) a steel coin (c) a wooden stick (d) a safety pin
15. 15.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the input (b) the process (c) the battery (d) the output
16. 16.🤖 Does a plain wall switch usually have a microcontroller inside? (a) Yes (b) No
17. 17.True or false: to use small battery cells is safe. (a) False (b) True
18. 18.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) input (b) output (c) process
19. 19.True or false: the ammeter measures voltage. (a) False (b) True
20. 20.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) parallel (b) series
21. 21.True or false: “a knob turned part way” is a digital signal. (a) True (b) False
22. 22.🔍 Which is the odd one out? (a) use small battery cells (b) use mains for a project (c) fly kites in open fields (d) stop if a part gets hot
23. 23.🧮 A 100 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)?
24. 24.✏️ In a circuit diagram, which part is drawn as a circle with a cross? (a) cell (b) bulb (c) junction (d) switch
25. 25.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
26. 26.True or false: on an LED, the round-side leg is the cathode (−). (a) False (b) True
27. 27.🔍 Which is the odd one out? (a) a water pump (b) a small display (c) a push button (d) an LED
28. 28.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
29. 29.⏱️ loop forever { LED ON; wait 700 ms; LED OFF; wait 600 ms }
    How many milliseconds does one blink (ON + OFF) take?
30. 30.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) so all go off together (d) to make bulbs dim
31. 31.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = I ÷ R (d) V = R ÷ I
32. 32.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) open (b) closed
33. 33.Which of these is measured in volts (V)? (a) resistance (b) the push of a cell (c) energy used each second (d) power
34. 34.Which job needs a rain sensor? (a) warn of a gas leak (b) switch on lamps at dusk (c) close a window in rain (d) water a dry plant
35. 35.🔌 Is a keypad an input or an output for a microcontroller? (a) input (b) output
36. 36.🤖 “if (A AND B)” is true when … (a) only A is true (b) both A and B are true (c) only B is true (d) both are false
37. 37.True or false: to cover unused cameras is a good habit. (a) False (b) True
38. 38.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to limit the current (d) to change its colour
39. 39.🌐 Is a Wi-Fi smart plug an IoT device? (a) not an IoT device (b) an IoT device
40. 40.💡 2 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =

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