An electric conductor is a type of material that allows electric current through it freely in one or more directions.
Imagine a water pipe as a conductor,, water pressure as a voltage, and water as a charge carrier. Here the pipe allows water to pass through it freely; similarly, the conductors allow electric charge to pass through it freely.

1.1 : Measurent of Conductor

The conductor is measured in two different types. One is cross-sectional area, which is physical measurement, and wire gauge, which is a standardized number system.

1.1.1 Cross sectional area

The cross-sectional area of a conductor is typically measured in square inches (sq in) or circular mils (c mil), and it is calculated using the formula A =πr².
Imagine a water pipe that has some amount of cross-sectional area for water flow. The large cross-sectional area means more space and a greater amount of water flow; similarly, the large cross-sectional area allows more current to flow freely through the conductor safely.

1.1.2 Wire Gauge

A wire gauge is an indirect measurement of the area of a conductor that is measured using standardized measurements such as the as the American wire gauge system and the Standard wire gauge system. By using a wire gauge system and taking a wire gauge table as a reference, we can measure the resistance, cross-sectional area, and diameter of a conductor. In the wire gauge system, a lower number indicates the thicker wire, and a higher number indicates the thinner wire.

1.1.3 Types of material used for Conductor

There are different materials used for conductors for different applications based on their advantages and disadvantages. Some popular materials are listed below with their applications.

Metals:

1. Copper: The most widely used conductor due to its excellent conductivity, good workability, and relatively low cost. It's found in electrical wiring, cables, busbars, and transformers.

2. Aluminum: A lighter and cheaper alternative to copper, but with lower conductivity. Common in overhead power lines due to its weight advantage and sufficient conductivity for long-distance transmission.

3. Silver: The best conductor in terms of conductivity, but also the most expensive. Primarily used for specialized applications like high-frequency circuits or when weight is a critical factor (aerospace).

4. Gold: Excellent conductor with good corrosion resistance. Used in electrical connectors, integrated circuits, and applications requiring high reliability due to its resistance to tarnishing.

Alloys:

1. Brass and Bronze: Excellent conductor with good corrosion resistance. Used in electrical connectors, integrated circuits, and applications requiring high reliability due to its resistance to tarnishing.

Other Materials:

1.Graphite : A good conductor in its pure form. Used in brushes for electric motors and grounding applications.

2. Electrolytes: Solutions that allow ionic conduction. Used in batteries, fuel cells, and electroplating.

3. Super conductors: Certain materials that exhibit zero electrical resistance at very low temperatures. Still under development for practical applications in power transmission and high-field electromagnets.