Which heating method does an induction furnace use to melt metals?

Which heating method does an induction furnace use to melt metals?

• A. Uses direct flame to heat the metal
• B. Uses AC through a coil wrapped around the vessel to generate heat by induction
• C. Uses electrical resistance coils around the furnace
• D. Relies on chemical reduction

Answer: (B)

Induction heating relies on electromagnetic induction to melt metal. An alternating current flows through a coil wrapped around the furnace vessel, creating a changing magnetic field. This field induces electrical currents inside the metal, and the metal’s resistance converts that electrical energy into heat. The heat is generated directly in the metal (and, for ferrous metals, aided by hysteresis losses), so no open flame or external heating surface is needed. This makes heating efficient, controllable, and clean compared to methods that use flames or external resistive elements. The other concepts—direct flame, heating by resistance in coils around the furnace, or relying on chemical reduction—do not describe how induction furnaces actually heat the metal.

Induction heating relies on electromagnetic induction to melt metal. An alternating current flows through a coil wrapped around the furnace vessel, creating a changing magnetic field. This field induces electrical currents inside the metal, and the metal’s resistance converts that electrical energy into heat. The heat is generated directly in the metal (and, for ferrous metals, aided by hysteresis losses), so no open flame or external heating surface is needed. This makes heating efficient, controllable, and clean compared to methods that use flames or external resistive elements. The other concepts—direct flame, heating by resistance in coils around the furnace, or relying on chemical reduction—do not describe how induction furnaces actually heat the metal.