What is the effect of hysteresis?
The magnetization of ferromagnetic substances due to a varying magnetic field lags behind the field. This effect is called hysteresis, and the term is used to describe any system in whose response depends not only on its current state, but also upon its past history.
Is an example of hysteresis?
For example, if a thermostat set for 70 degrees turns on when the temperature reaches 68 and turns off at 72, the hysteresis is the range from 68 to 72.
What is the use of hysteresis loop?
Hysteresis loop provides the value of retentivity and coercivity of a material. Thus the way to choose perfect material to make permanent magnet, core of machines becomes easier. From B-H graph, residual magnetism can be determined and thus choosing of material for electromagnets is easy.
Why is it called hysteresis loop?
If an alternating magnetic field is applied to the material, its magnetization will trace out a loop called a hysteresis loop. The lack of retraceability of the magnetization curve is the property called hysteresis and it is related to the existence of magnetic domains in the material.
What do you mean by hysteresis loop?
hysteresis loop in British English noun. a closed curve showing the variation of the magnetic flux density of a ferromagnetic material with the external magnetic field producing it, when this field is changed through a complete cycle.
How hysteresis loop is formed and what is its significance?
When a specimen of magnetic material is magnetised, a curve is drawn for magnetic field intensity (H) against intensity of magnetisation (I). The curve so formed is called Hysteresis Loop. It is called hysteresis because of lagging of I behind H during the cycle of magnetisation.
What is the purpose of plotting the magnetization curve?
As you raise the primary current the tip of the hysteresis loop traces out a normal magnetization curve. It is similar in shape to the initial magnetization curve, and is a convenient way of describing the material behavior.
Why does saturation curve starts from some value higher than zero?
Electrical Question 3: Why Saturation Curve for the DC Generator does not start with zero ? This curve starts from a point which is slightly higher than the origin representing that there is some flux produced by the field poles even no current is passed through the field windings.
Why DC generator are loosing their residual magnetism?
Residual magnetism in the generator exciter field allows the generator to build up voltage during start-up. This magnetism is sometimes lost due to shelf time or improper operation, among other reasons. Restoring this residual magnetism is possible and is sometimes referred to as “flashing the exciter field”.
What is the meaning of magnetization?
noun The process of making a substance temporarily or permanently magnetic, as by insertion in a magnetic field. noun The extent to which an object is magnetized. noun The property of being magnetic.
What is the difference between magnetization and demagnetization?
When we magnetized permanently or temporarily of the ferromagnetic substance then it process is called magnetization. When a piece of iron touches to a magnet then the iron piece will be magnetized. Demagnetization : When we remove the magnetic property of the magnet it process is called demagnetization.