How a resistance furnace generates heat: Identify the fundamental heating mechanism inside an electric resistance furnace.

Introduction / Context:
Electric furnaces are grouped by how they transform electrical energy into heat. Resistance furnaces rely on ohmic heating of elements, arc furnaces on high-current arcs, and induction furnaces on electromagnetic induction and skin effect within the charge.

Given Data / Assumptions:

• Standard resistance elements (e.g., Kanthal, SiC, MoSi₂).
• Temperature controlled by power to the elements.
• Charge heated by radiation and convection from hot elements and walls.

Concept / Approach:
In a resistance furnace, current passes through a high-resistivity element. Electrical power P is converted to heat as P = I^2 * R or P = V^2 / R. The resulting element temperature provides radiant and convective heat to the load. There is no arc between electrodes and charge (that would be an arc furnace), nor are eddy currents induced in the charge (that would be induction).

Step-by-Step Solution:

Verification / Alternative check:
Manufacturer datasheets specify element resistance, allowable current, and power density—hallmarks of resistance heating.

Why Other Options Are Wrong:

Common Pitfalls:
Confusing the heat delivery (radiation to the load) with the generation mechanism (Joule heating in elements).

Final Answer:
flow of current through a heating element.