# Electrical Terms

## EMF Equation of a Transformer

When a sinusoidal voltage is applied to the primary winding of a transformer, alternating flux ϕm sets up in the iron core of the transformer. This sinusoidal flux links with both primary and secondary winding. The function of flux is a sine function. The rate of change of flux with respect to time is derived …

## Working Principle of a Transformer

The basic principle on which the transformer works is Faraday’s Law of Electromagnetic Induction or mutual induction between the two coils. The working of the transformer is explained below. The transformer consists of two separate windings placed over the laminated silicon steel core. The winding to which AC supply is connected is called primary winding …

## Magnetic Hysteresis

The phenomenon of flux density B lagging behind the magnetizing force H in a magnetic material is known as Magnetic Hysteresis. The word Hysteresis is derived from the Greek word Hysterein means to lag behind. In other words, when the magnetic material is magnetized first in one direction and then in the other direction, completing …

## Ideal Transformer

Definition: The transformer which is free from all types of losses is known as an ideal transformer. It is an imaginary transformer that has no core loss, no ohmic resistance, and no leakage flux. The ideal transformer has the following important characteristic. The resistance of their primary and secondary winding becomes zero. The core of the …

## What is a Transformer

A Transformer is a static electrical machine which transfers AC electrical power from one circuit to the other circuit at the constant frequency, but the voltage level can be altered that means voltage can be increased or decreased according to the requirement. It works on the principle of Faraday’s Law of Electromagnetic Induction which states …

## Eddy Current Loss

When an alternating magnetic field is applied to a magnetic material, an emf is induced in the material itself according to Faraday’s Law of Electromagnetic induction. Since the magnetic material is a conducting material, these EMFs circulate current within the body of the material. These circulating currents are called Eddy Currents. They will occur when …

## Residual Magnetism

Residual magnetism is defined as the amount of magnetization left behind after removing the external magnetic field from the circuit. In other words, the value of the flux density (ob as shown in the figure with the red colour line) retained by the magnetic material is called Residual Magnetism and the power of retaining this …

## Hysteresis Loss

Definition: The work done by the magnetising force against the internal friction of the molecules of the magnet, produces heat. This energy which is wasted in the form of heat due to hysteresis is called Hysteresis Loss.  When in the magnetic material, magnetisation force is applied, the molecules of the magnetic material are aligned in …

## Parallel Magnetic Circuit

Definition: A magnetic circuit having two or more than two paths for the magnetic flux is called a parallel magnetic circuit. Its behaviour can be compared to the parallel electric circuit. The parallel magnetic circuit contains different dimensional areas and materials having various numbers of paths. The above figure shows a parallel magnetic circuit. In …

## Series Magnetic Circuit

Definition: The Series Magnetic Circuit is defined as the magnetic circuit having a number of parts of different dimensions and materials carrying the same magnetic field. Consider a circular coil or solenoid having different dimensions as shown in the figure below: Current I is passed through the solenoid having N number of turns wound on …