Meaning of Permeability (μ) in Magnetic Materials Evaluate the statement: “The permeability of a core material indicates the ability of the material to establish (support) a magnetic field.”

Introduction / Context:
Permeability (μ) is fundamental in electromagnetics and magnetic circuit design. It influences inductance, transformer behavior, and the confinement of magnetic flux. This question checks conceptual understanding of how μ characterizes a material’s magnetic response.

Given Data / Assumptions:

• Magnetostatics or low-frequency magnetic behavior in linear regions.
• Relationship between magnetic flux density B and magnetic field intensity H.
• Homogeneous material approximation for clarity.

Concept / Approach:

The constitutive relation is B = μ H, where μ = μ_0 μ_r. A higher μ means the material supports a larger magnetic flux density B for the same applied field H. Thus, permeability is a measure of how readily the material “conducts” magnetic flux, akin to electrical conductivity for current but in the magnetic domain (with important differences).

Step-by-Step Solution:

Verification / Alternative check:

Transformer and inductor cores use materials with μ_r » 1 (e.g., ferrites) to concentrate flux and achieve higher inductance in compact volumes. Air, with μ_r ≈ 1, provides much lower flux density for the same H, confirming the meaning of μ.

Why Other Options Are Wrong:

“False” denies the B–H relation. “True only for ferromagnets” is too restrictive; the definition applies to all media (though μ_r may be close to 1 for paramagnetic/diamagnetic materials). “True only at DC” is unnecessary; μ applies at AC as well, although it can be frequency dependent. “Permeability relates to electric field” is incorrect—that is permittivity (ε).

Common Pitfalls:

Confusing permeability with permittivity, or assuming μ is constant across all fields and frequencies (real cores are nonlinear and dispersive).

Final Answer:

True