Electronics Basics Quiz

Test your Arduino fundamentals with 15 comprehensive questions

About This Quiz

🎯 Purpose: Check your understanding of resistors, LEDs, voltage, current, and breadboard connections.

📊 Format: 15 multiple-choice questions

⏱️ Time: ~10 minutes

🧪 Tip: Think about basic electronics principles and Ohm's Law!

Score: 0 / 15

1. What is the purpose of a resistor in a circuit?

A) To increase current B) To limit current flow C) To store energy D) To generate voltage

Resistors limit current to protect components and set operating points.

2. What happens if an LED is connected without a resistor?

A) It glows brighter safely B) It may burn out due to too much current C) It will not turn on D) It will blink automatically

LEDs require current limiting; otherwise they can overheat and fail.

3. In an Arduino circuit, where should the LED’s cathode (C) be connected?

A) To the 5V pin B) To the ground (GND) C) To digital pin 13 D) To the resistor

Cathode typically goes to ground; anode goes to the positive side through a resistor.

4. The anode (A) of an LED connects to:

A) Ground B) Negative terminal C) Positive voltage through a resistor D) Analog input pin

The resistor limits current from the positive supply into the LED’s anode.

5. If voltage increases but resistance stays the same, what happens to the current?

A) It decreases B) It stays the same C) It increases D) It becomes zero

Ohm’s Law: I = V / R. With R constant, increasing V increases I.

6. Which color wire is typically used for ground in breadboard circuits?

A) Red B) Blue C) Green D) Black

Convention: black for GND, red for +V. (You can choose any, but be consistent.)

7. The resistor in this circuit has a value of 220 Ω. What is its main function?

A) Reduce LED brightness and protect it B) Supply more power to the LED C) Store charge D) Measure voltage drop

A series resistor limits current; brightness drops as current is limited.

8. What does voltage represent in a circuit?

A) The number of electrons B) The push or force that moves electrons C) The resistance of the wires D) The brightness of the LED

Voltage is the electric potential difference—the “push.”

9. What happens if you swap the LED’s anode and cathode connections?

A) It will still work normally B) It won’t light up C) It will blink faster D) It will get brighter

LEDs are polarized; reverse‑bias prevents current flow (and light).

10. In the Wokwi connection diagram, pin 13 of the Arduino is used to:

A) Power the LED directly B) Control the LED as a digital output C) Read analog voltage D) Connect to ground

Pin 13 can be set HIGH/LOW to switch the LED via a resistor.

11. What are the long horizontal rows on a breadboard usually used for?

A) Power and ground connections B) Data transfer C) Analog inputs D) Resistor placement only

These are power rails to distribute +V and GND along the board.

12. What are the vertical columns in the center section of a breadboard called?

A) Power rails B) Terminal strips C) Connection rails D) Bus lines

Terminal strips are the main grid where components connect.

13. How are the holes connected inside a breadboard’s main area (the middle section)?

A) All holes are connected together B) Holes in each row are connected C) Holes in each column are connected D) Only corner holes are connected

Each 5‑hole column is tied together; the center gap separates left/right.

14. If you place a resistor across the gap in the middle of the breadboard, what are you doing?

A) Creating a short circuit B) Connecting components on both sides C) Disconnecting both sides D) Measuring current flow

Bridging the center gap links separate terminal strips in one path.

15. Why is a breadboard called a “breadboard”?

A) It was originally used to make bread B) It looks like a loaf of bread C) Early experimenters used wooden breadboards to build circuits D) It has a bread‑like texture

Historically, hobbyists nailed terminals into wooden breadboards to prototype.

Answer Key & Explanations