Induction electric furnaces — effect of induced currents and skin effect The electric furnace that develops heat by both induced currents and the skin effect is best described as which type?

Introduction / Context: Induction furnaces heat conductive charges via eddy (induced) currents generated by a time-varying magnetic field. At higher frequencies, current crowds near the surface (skin effect), intensifying surface heating and stirring (in coreless types).

Given Data / Assumptions:

• We compare heating mechanisms across furnace types.
• Skin depth decreases with frequency, heightening skin effect at high frequency.

Concept / Approach: Arc furnaces use arc radiation/resistance of the arc column; resistance furnaces heat via Joule heating in elements or the charge. Induction furnaces exploit induced currents; at high frequency, skin effect becomes pronounced, raising surface power density and enabling rapid melting/heating of metals.

Step-by-Step Solution:

Verification / Alternative check: Skin depth δ ∝ 1/√f; therefore, higher frequency reduces δ, intensifying surface current density and heating, matching high-frequency induction furnaces.

Why Other Options Are Wrong:

Common Pitfalls: Assuming all induction furnaces behave identically regardless of frequency; frequency selection is central to heating profile and penetration.

Final Answer: high frequency induction