Magnetic circuits: a ferromagnetic material such as iron provides a high-permeability path that can redirect or concentrate magnetic lines of force. Judge this statement.

Introduction / Context:
Transformers, inductors, and magnetic shields exploit high-permeability materials to guide magnetic flux. The statement claims that iron can change the course (path) of magnetic lines of force, which reflects practical magnetic circuit design.

Given Data / Assumptions:

• Iron or similar ferromagnets have relative permeability much greater than air.
• We consider fields below saturation for linear reasoning.
• No permanent magnetization is required to demonstrate flux guidance.

Concept / Approach:
Magnetic flux prefers paths of least reluctance, analogous to current choosing paths of least resistance. Since ferromagnetic materials have high permeability, their reluctance is low, attracting and guiding flux. C-cores, E-cores, and closed magnetic paths in transformers exemplify this principle by confining and redirecting field lines to improve coupling and reduce leakage.

Step-by-Step Solution:

Verification / Alternative check:
Field plots (finite-element simulations) and simple iron filings experiments show flux concentration near iron pieces and redirection along cores and shields.

Why Other Options Are Wrong:
Incorrect: ignores basic magnetic circuit behavior.

Requires permanent magnetization or cryogenic temperatures: flux guidance is due to permeability, not necessarily due to remanent magnetization or extreme temperatures.

Common Pitfalls:
Equating “lines of force” with physical strings; they are visualizations of field direction and density. Forgetting saturation, which limits flux guidance when B approaches material limits.

Final Answer:
Correct