Magnetic materials – is a ferromagnetic material one that “forms a resistance” to magnetic fields?

Introduction / Context:
While this topic appears under shift-registers, it references basic physics of materials. Ferromagnetism is a material property crucial to transformers, inductors, and magnetic storage. The statement suggests that ferromagnetic materials “form a resistance to magnetic fields,” which confuses electrical resistance with magnetic behavior.

Given Data / Assumptions:

• Ferromagnetic materials include iron, cobalt, nickel, and alloys.
• Key traits: large positive magnetic susceptibility and domain alignment.
• Temperature can affect ferromagnetism (Curie temperature), but the definition remains.

Concept / Approach:
Ferromagnetic materials strongly attract magnetic fields and can retain magnetization due to domain alignment; they do not resist magnetic fields in the sense implied. A more appropriate term in magnetics is reluctance, the magnetic analog of resistance, but ferromagnetic cores are used precisely because they offer low reluctance paths that concentrate flux, not high “resistance.” The statement therefore mischaracterizes ferromagnets and conflates electrical resistance with magnetic circuit concepts.

Step-by-Step Solution:

Verification / Alternative check:
In transformers, ferromagnetic cores concentrate magnetic flux and reduce magnetizing current—behavior opposite to “resisting” a magnetic field. The B–H curve shows high permeability regions where small applied field produces large flux density.

Why Other Options Are Wrong:
“Correct” flips physics. Temperature and initial magnetization do not turn ferromagnets into field resistors. Electrical resistivity is a different material parameter from magnetic permeability.

Common Pitfalls:
Mixing up electrical resistance with magnetic reluctance/permeability; assuming “ferro” means blocking fields. Remember: ferromagnets are chosen to channel magnetic flux.

Final Answer:
Incorrect