# What is eddy current and hysteresis?

Eddy current loss. Phenomenon. Hysteresis loss is caused due to molecular friction in a ferromagnetic material, under alternating magnetic field. Eddy current loss us caused due to the induction of eddy current in the core and conductors held in magnetic field.

## What is meant by eddy currents?

Eddy currents are loops of electrical current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field.

## What is hysteresis explain?

Hysteresis is characterized as a lag of magnetic flux density (B) behind the magnetic field strength (H). All ferromagnetic materials exhibit the phenomena of hysteresis. To give you a better understanding of the concept, we will take an instance where a ferromagnetic substance is placed inside a current-carrying coil.

## What is hysteresis in a transformer?

Key Takeaways. Hysteresis loss in a transformer occurs due to magnetization saturation in the core of the transformer. Magnetic materials in the core will eventually become magnetically saturated when they are placed in a strong magnetic field, such as the magnetic field generated by an AC current.

## Why is it called eddy current?

This new magnetic field repels the original magnetic field, therefore creating a damping effect. The strongest point of an eddy current is at the surface of a conducting material and flows in small circles representing 'eddies' in a stream – hence the name 'eddy current'!

## What is eddy current formula?

Next, the eddy current flowing in each ring is obtained by solving a complex matrix equation of the form [X] [I] = [V] where X is the impedance matrix, I is the eddy current matrix, and V is the induced voltage matrix.

## What causes hysteresis loss?

Hysteresis loss is caused by the magnetization and demagnetization of the core as current flows in the forward and reverse directions. As the magnetizing force (current) increases, the magnetic flux increases.

## What is eddy current loss?

If an eddy current of magnitude I flows through a core path of resistance r, it will dissipate energy in the form of heat according to the power equation power = I2R. Since this represents energy being expended for no useful purpose, it is considered as an eddy current loss, sometimes called iron loss.

## What is retentivity and coercivity?

Retentivity: The property of the magnetic material to retain magnetism even in the absence of the magnetizing field is known as retentivity or remanence. Coercivity: The magnetizing field (H) needed to demagnetize the magnetic material completely is known as its coercivity.

## What are the 3 types of losses in transformer?

Types of Losses in a Transformer
• Iron Losses in a Transformer. Iron losses mainly occur through the alternating flux within the transformer's core. ...
• Copper Loss. Copper losses occur because of the Ohmic resistance in the windings of the transformer. ...
• Stray Loss. ...
• Dielectric Loss. ...
• Efficiency of Transformer.

## What is hysteresis in material?

Elastic Hysteresis is the difference between the strain energy required to generate a given stress in a material, and the material's elastic energy at that stress. This energy is dissipated as internal friction (heat) in a material during one cycle of testing (loading and unloading).

## What is hysteresis in magnetic material?

Magnetic hysteresis occurs when an external magnetic field is applied to a ferromagnet such as iron and the atomic dipoles align themselves with it. Even when the field is removed, part of the alignment will be retained: the material has become magnetized. Once magnetized, the magnet will stay magnetized indefinitely.

## What is meant by hysteresis Class 12?

Hysteresis - The condition in which the magnetic induction 'B' lags behind the magnetizing field H is called hysteresis. This happens when an external magnetic field is applied to a ferromagnet such as iron and the atomic dipoles are aligned with it.

## What is eddy current and its application?

Eddy currents are sometimes so strong, that metallic plate become red hot. Application:- (1)-In induction furnace, the metal to be heated is placed in rapidly varying magnetic field produced by high frequency alternating current. Strong eddy currents are set up in the metal produce so much heat that the metal melts.

## What is eddy current and applications?

Its main applications are induction cooking, induction furnace used to heat metals to their melting point, welding, brazing etc. Eddy Current Adjustable Speed Drives: With the help of feedback controller an eddy current coupled speed drive can be achieved.

## What is eddy current in 12th physics?

Eddy currents are induced currents in the body of conductor when subjected to changing magnetic flux. They are also known as Foucault current after the name of the scientist Foucault. They are known as eddy currents as they are in the pattern of eddiesin the water.

## What is BH curve?

The B-H curve or magnetisation curve is the graph plotted between magnetic flux density (B) and magnetising force (H). The B-H curve indicates the manner in which the magnetic flux density varies with the change in magnetising force.

## What coercivity means?

British Dictionary definitions for coercivity

coercivity. / (ˌkəʊɜːˈsɪvɪtɪ) / noun. the magnetic-field strength necessary to demagnetize a ferromagnetic material that is magnetized to saturation. It is measured in amperes per metreCompare coercive force.

## What is hysteresis define coercivity and retentivity?

Hysteresis: The phenomenon of lagging behind the magnetic induction (→B ) with respect to the magnetizing field (→h ) is called hysteresis. Retentivity: The property of the magnetic material to retain magnetism even in the absence of the magnetizing field is known as retentivity or remanence.

## What is the formula of hysteresis loss?

The hysteresis loss per second is given by the equation: Hysteresis loss, Ph= (Bmax)1.6f V joules per second (or) watts. Where, f: supply frequency in Hz, V: volume of core in cubic meters, η‟: hysteresis coefficient, Bmax: peak value of flux density in the core.

## How can we reduce hysteresis and eddy current loss?

The eddy current loss occurs because of the interaction of magnetic field and conductor. The hysteresis loss occurs because of the reversal of the magnetism. The eddy current loss is minimised by using the thin core of lamination. The silicon steel material is used for minimising the hysteresis loss.

## What is difference between eddy current and induced current?

The main difference between eddy current and induced current is that induced current refers to currents flowing in coils of wire in a closed circuit whereas eddy current refers to loops of currents flowing within pieces of larger conductors due to electromagnetic induction.

## Why are eddy currents circular?

Eddy currents are always circular in nature because of the reason that current always prefers to take least resistive path. As it is known that for same area of circle and any other finite sided polygon, circle has the least perimeter.

## What is Curie's law class 12?

According to Curie's Law, the magnetization in a paramagnetic material is directly proportional to the applied magnetic field. If the object is heated, the magnetization is viewed to be inversely proportional to the temperature. The law was discovered by the French physicist, Pierre Curie.