Difference Between Flux and Flux Linkage

Flux vs Flux Linkage
 

Flux and flux linkage are two very important concepts discussed in the electromagnetic theory. Flux is the amount of the field through a particular surface. Flux linkage is the fraction of the outgoing flux from the source to the captured flux from the drain. Both of these ideas are very important in fields such as electromagnetic, power and electrical engineering, physics and many more fields. A thorough understanding in these concepts is required in order to excel in such fields. In this article, we are going to discuss what flux and flux linkage are, their definitions, the similarities of flux and flux linkage and finally the difference between flux and flux linkage.

What is Flux?

Flux is a conceptual property. In fields such as electric, magnetic, electromagnetic, and gravitational field, a term called flux is defined in order to describe the field. To understand what flux is one must first understand the lines of force. For an example, magnetic field lines or magnetic lines of forces are a set of imaginary lines, which are drawn from N (north) pole of the magnet to the S (south) pole of the magnet. In definition, these lines never cross each other unless the magnetic field intensity is zero. It must be noted that magnetic lines of forces are a concept. They do not exist in real life. It is a model, which is convenient to compare magnetic fields qualitatively. For electric fields, the lines are drawn from the positive end to the negative end. The flux over a surface is said to be proportional to the number of lines of forces perpendicular to the given surface. The flux is denoted by the Greek letter ψ. The concept of flux holds a very special place in the electromagnetic induction. In electromagnetic induction, the current flowing through a closed conducting loop is proportional to the rate change of magnetic flux over the closed surface, which is created by the conducting loop.

What is Flux Linkage?

Flux linkage is a property, which is very important in electromagnetic induction. Imagine a conducting wire, which makes a closed loop. The wire can be of any shape. The flux linkage of the wire is the flux going through the closed surface created by the boundary of the wire. Assume that the flux density of the magnetic field is B and a circular coil having N turns is placed normal to the magnetic field. The flux linkage of the coil is the product of the flux density, area of the circle, and the number of turns. The electromotive force generated inside the loop is proportional to the rate change of the flux through the area or rate change of flux linkage.