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5. What is Hysteresis Curve? what is hysteresis loop in hindi

# What is Hysteresis Curve? what is hysteresis loop in hindi

Hello friends In this article we will know what is Hysteresis Loop? And how is it made? And learn about many facts related to it.

## Hysteresis Loop

Magnetic material is magnetized due to its permeability property. By increasing the magnetization force from zero to maximum (Hmax) and again in reverse direction of magnetization, reducing the magnetization force to minimum (-Hmax) and again to zero, the BH curve is a closed loop called hysteresis loop.

When a magnetic material is magnetic field (Alternating Magnetic feild), then there are two types of losses in it –

1. Hysteresis Losses
2. Eddy Current Loss

The flux density-magnetisation curve in one cycle of magnetization in the alternating field of a specimen is obtained as shown in the figure.

It is known from the hysteresis curve that initially the magnetic induction ‘B’ increases rapidly with the increase of magnetization and then gradually increases and the saturation value ‘B’max‘ But it settles down. On reversing the direction of the magnetizing force, ‘B’ gradually decreases and at zero magnetization (H = 0) there is a residual magnetism B.R remains equal to.

It represents the magnetization retained by the material upon removal of the magnetic field and is a measure of the retentivity of the material. If the magnetizing field (H) is continuously increased in the distributed direction, then the domains of the material try to disalign and have a particular value of H.C But the magnetization of the substance becomes zero, this force is called Coercive force.

When the magnetic field is again increased in the opposite direction, the magnetization of the material starts happening in the opposite direction and after saturation in the opposite direction, the Hysteresis Loop is completed when the field is increased in the first direction.

The area of ​​this loop is proportional to the energy expenditure in one cycle of magnetization and demagnetization of the material.

The total hysteresis losses in the volume ‘V’ of the material at magnetic frequency f is represented by the following formula:

Wh = loop area × f × V watt
= Bmax 1.6 watt

## The hysteresis loop depends on –

1. Volume of magnetic material (V)
2. Highest value of flux density (Bmax,
3. Frequency Of Magnetisation
4. grade of magnetic material (η)

There are three hysteresis loops in the figure

• The area of ​​loop (1) is very small. This means that losses in this material are less, i.e. iron, silicon, mumetal etc.
• The second loop (2) is for wrought iron or cast steel. These substances have high permeability. The large intercept on axis B exhibits high retentivity of the material.
• Loop (3) is for hard steel; Large area of ​​the loop shows high hysteresis losses but is suitable for permanent magnets due to high coercive force.

### What is a Hysteresis Curve?

The hysteresis curve is formed between the magnetic force and the flux density. It is also called BH curve.