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Fill in the blank: The _____ occurs in a magnetic material because the magnetic flux density lags behind the magnetizing force as the current cycle progresses.
Hysteresis loss
Eddy current loss
Ohmic loss
Skin effect
Hysteresis loss
Hysteresis loss is the energy dissipated as heat when a magnetic material is subjected to a cyclic magnetizing force. It occurs because the magnetic domains within the material do not reorient instantaneously with the external field, causing the magnetic flux density B to lag behind the magnetizing force H.
IS 648:2009 (Magnetic materials)
Hysteresis loss is the energy dissipated as heat when a magnetic material is subjected to a cyclic magnetizing force. It occurs because the magnetic domains within the material do not reorient instantaneously with the external field, causing the magnetic flux density B to lag behind the magnetizing force H.
WhтАЛ=╬╖тЛЕBmax1.6тАЛтЛЕfтЛЕV тАФ Steinmetz's empirical formula for hysteresis loss
Area=тИоHтЛЕdB тАФ Energy loss per unit volume per cycle
When an alternating current flows through a coil, the internal molecular magnets (domains) of the core material are forced to flip repeatedly. The energy consumed in overcoming the internal friction between these domains manifests as heat, represented by the area enclosed by the BтИТH hysteresis loop.
The area of the BтИТH loop is directly proportional to the energy dissipated as heat per cycle.
Hard magnetic materials have a wide hysteresis loop, indicating high hysteresis loss.
Soft magnetic materials (like silicon steel) are used in transformers due to their narrow hysteresis loops, minimizing energy loss.
Hysteresis loss depends on the frequency of the magnetic field reversal.
Wide loops are useful for permanent magnets.
Small loops indicate energy-efficient materials for electrical machines.
Increases heat in electrical machines.
Reduces overall efficiency of power transformers and rotating machines.
Transformer core design
Magnetic storage media
Option B (Eddy current loss) occurs due to induced currents in the core, not the lag between B and H.
Option C (Ohmic loss) is I2R loss in the conductor.
Option D (Skin effect) is the phenomenon where AC current concentrates near the surface of a conductor.
A is correct тАФ Hysteresis loss is the result of the magnetic domain friction caused by the phase lag between magnetizing force and flux density.
Always remember that hysteresis loss is proportional to the frequency f and the area of the loop, whereas eddy current loss is proportional to f2.
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