What are the units of flux?

Flux is a fundamental concept in physics and engineering. It refers to the flow of a physical quantity through a surface or across a boundary. The units of flux depend on the specific quantity being measured. In this article, we will explore the various units of flux for different physical phenomena.

1. Electrical Flux

In the field of electromagnetism, electrical flux measures the flow of electric field lines through a surface. It is calculated as the dot product of the electric field vector and the area vector. The unit of electrical flux is volt meters squared (V·m²) or weber (Wb). One weber of electrical flux passing through a surface means that one volt of electric potential difference exists across that surface.

2. Magnetic Flux

Magnetic flux represents the flow of magnetic field lines through a surface. It is calculated as the dot product of the magnetic field vector and the area vector. The unit of magnetic flux is weber (Wb), which is equivalent to one tesla meter squared (T·m²). A magnetic flux of one weber passing through a surface means that there is a magnetic field of one tesla threading through that surface.

3. Heat Flux

Heat flux, also known as thermal flux, quantifies the rate at which heat energy flows through a surface. It is measured in watts per square meter (W/m²) or joules per second per square meter (J/(s·m²)). Heat flux can be both convective and radiative. Convective heat flux is associated with fluid motion, while radiative heat flux is due to electromagnetic radiation transfer.

4. Mass Flux

Mass flux, sometimes called mass flow rate, represents the flow of mass through a unit area. It is measured in kilograms per second per square meter (kg/(s·m²)). Mass flux is commonly used in fluid dynamics to describe the movement of fluids, such as gas or liquid, through a surface.