Definition of magnetic permeability – identifying a permeable substance Select the statement that best describes a permeable substance in the context of magnetism and magnetic circuits.

Introduction:
Permeability is a measure of how readily a material supports the formation of a magnetic field within itself. In magnetic circuit design, choosing a material with suitable permeability allows efficient guiding and concentrating of flux paths, just like conductivity guides electric current in electric circuits.

Given Data / Assumptions:

• Permeable materials possess higher µ than free space (µ > µ0) for ferromagnets.
• Magnetic lines are a conceptual tool indicating direction and relative density of flux.
• No assumption of permanent magnetization is required.

Concept / Approach:

A “permeable” substance allows magnetic flux to pass more easily than in air, meaning it has higher permeability and can carry a higher flux density for a given magnetizing force. This is why iron and related alloys serve as cores to shape and intensify magnetic fields in transformers, motors, and inductors.

Step-by-Step Solution:

Verification / Alternative check:

Magnetic circuit analogies (Φ = F / Rm with reluctance Rm ∝ 1/µ) reinforce that larger µ means smaller reluctance and easier flux passage, aligning with the chosen description.

Why Other Options Are Wrong:

Being a “strong magnet” relates to remanence/coercivity, not permeability alone; good electrical conduction is unrelated; zero susceptibility implies vacuum-like behavior, not “permeable.”

Common Pitfalls:

Equating permeability with permanent magnetism; confusing electric and magnetic material properties.

Final Answer:

through which magnetic lines of force can pass easily