Which statement best distinguishes labyrinth seals from carbon seals?

• A. Labyrinth Seals Are Contact Seals; Carbon Seals Are Non-Contact
• B. Labyrinth Seals Are Non-Contact; Carbon Seals Provide A Carbon-Face Dynamic Seal
• C. Labyrinth Seals Rely On Magnetic Fields; Carbon Seals Use Oil Film
• D. Labyrinth And Carbon Seals Operate Identically

Answer: (B)

The key idea is how the seal blocks leakage. Labyrinth seals block flow through a complex, tortuous path and do not contact the rotating and stationary surfaces, so they’re non-contact seals that rely on geometry to restrict leakage. Carbon seals, by contrast, use carbon-faced mating surfaces that form a dynamic seal as the surfaces slide against each other, typically with a thin lubricating oil film between them. That sliding, oil-film–assisted contact characterizes a carbon-face dynamic seal.

So labyrinths are non-contact, while carbon seals rely on a carbon-face interface that seals dynamically during rotation. The other statements don’t fit because they either misstate the contact nature, introduce unrelated concepts like magnetic fields, or claim the seals operate the same way.