Question

Describe how the design of a vacuum flask keeps the liquid inside hot ?

Answer 1

The gap between the two flasks is partially evacuated of air, creating a near-vacuum which significantly reduces heat transfer by conduction or convection. Vacuum flasks are used domestically to keep beverageshot or cold.

Answer 2

the gap between the two flasks is partially evacuated of air creating a near vacuum which significantly reduces heat transfer by conduction or convection