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In order to minimise hysteresis loss, the magnetic material should have
High retentivity
Large B-H loop area
Low hysteresis co-efficient
High resistivity
Low hysteresis co-efficient
Quick Summary: Hysteresis loss in magnetic materials is directly proportional to the area of the B-H hysteresis loop. A material with a low hysteresis coefficient (Steinmetz coefficient) ensures a narrow loop, thereby minimizing the energy dissipated as heat during each cycle of magnetization and demagnetization.
Hysteresis loss in magnetic materials is directly proportional to the area of the B-H hysteresis loop. A material with a low hysteresis coefficient (Steinmetz coefficient) ensures a narrow loop, thereby minimizing the energy dissipated as heat during each cycle of magnetization and demagnetization.
PhтАЛ=╬╖fBmaxxтАЛV
Area of B-H loop тИЭ Hysteresis Loss
According to the Steinmetz hysteresis loss formula, the energy dissipated per unit volume per cycle is given by WhтАЛ=╬╖BmaxxтАЛ. Here, ╬╖ represents the hysteresis coefficient. By selecting materials with a small ╬╖, such as soft iron or silicon steel, we reduce the energy losses incurred by the molecular friction of magnetic domains rotating against the external field.
Hysteresis loss occurs due to the energy required to orient magnetic domains.
Soft magnetic materials exhibit low coercivity and narrow B-H loops.
Silicon steel is commonly used in transformers to maintain low hysteresis loss.
The exponent 'x' typically ranges between 1.6 to 2.0 based on the material.
Increased efficiency of electrical machines
Reduced heating of the magnetic core
High purity materials with low ╬╖ are often more expensive
Extreme magnetic softness can limit maximum flux density
Transformer cores
Inductor cores
Electric motor laminations
Option B is incorrect because a large B-H loop area implies high hysteresis loss (suitable for permanent magnets, not transformers).
Option D (High resistivity) is used to minimize Eddy Current loss, not hysteresis loss.
C is correct тАФ A low hysteresis coefficient (Steinmetz coefficient) results in a narrow B-H loop, which directly minimizes the energy lost as heat per cycle.
Always distinguish between hysteresis loss (reduced by material selection) and eddy current loss (reduced by laminating the core and increasing resistivity).