Magnetic Response Comparison – Silicon Steel vs Cast Iron A silicon steel specimen shows flux density B = 0.5 T when subjected to magnetic field strength H = 200 A/m. For a cast iron specimen under the same H, the resulting B would be:

Introduction / Context:
For magnetic materials, B = μ0 (H + M) or equivalently B = μ H in linear regions, where μ is the absolute permeability. Different ferromagnetic materials have different μ–H characteristics (B–H curves). Silicon steels are engineered to have high permeability and low hysteresis loss; cast irons generally have lower permeability and higher losses due to graphite/flakes or microstructure.

Given Data / Assumptions:

• Same applied field H = 200 A/m to two different materials.
• Observed B in silicon steel is 0.5 T.
• Compare typical μ for cast iron vs silicon steel in a comparable magnetization region.

Concept / Approach:

Under the same H, the material with higher μ develops a higher B. Silicon steels are optimized for transformer/alternator cores and typically exhibit higher initial and maximum permeability than cast irons. Therefore, for identical H, cast iron will generally show a lower B than silicon steel (except in unusual saturation or microstructural anomalies not implied here).

Step-by-Step Solution:

Verification / Alternative check:

Typical B–H curves confirm silicon steels reach higher B at the same H than cast iron before saturation.

Why Other Options Are Wrong:

• 0.5 T equal value would require equal permeability, unlikely here.
• More than 0.5 T contradicts lower μ of cast iron.
• “Cannot say” ignores standard comparative material behavior.

Common Pitfalls:

Confusing permeability trends at different H regions; overlooking microstructural dependence but assuming identical H still favours higher-μ materials.

Final Answer:

Less than 0.5 T