Voltage, more precisely known as electric potential difference, is a fundamental concept in electromagnetism. It signifies the potential energy difference between two points in an electric field.

Formal Definition:

Voltage (V) is the amount of work (W) required to move a unit of positive charge (q) from one point to another within an electric field. Mathematically:

V = W / q

Units:

The SI unit of voltage is the volt (V). One volt represents the potential difference where one joule (J) of work is done to move one coulomb (C) of charge.

Relationship with Other Quantities:

Voltage plays a crucial role in understanding electrical circuits and is interrelated with other fundamental quantities:

Current (I): Voltage drives the flow of electric current (I) through a conductor. The relationship is described by Ohm's Law: V = I * R, where R is the resistance of the conductor.
Electric Field (E): Voltage can be interpreted as the negative line integral of the electric field (E) along a path between two points:

V = -∫ E . dr

Types of Voltage:

There are two main types of voltage:

Direct Current (DC): Voltage with a constant value and direction, like in batteries.
Alternating Current (AC): Voltage that periodically reverses its direction, like in household outlets.

Points:

Voltage is a scalar quantity, meaning it only has magnitude and no direction.
Higher voltage indicates a greater potential difference and can cause a larger current to flow through a conductor (assuming constant resistance).
Voltage plays a vital role in various electrical phenomena like energy transfer, power generation, and signal transmission.