Question

Thermal conductivity of air is less than that of felt but felt is a better insulator why?

Answer 1

Hint: Felt is a bit fibrous fluffy substance having numerous holes which trap much air. However, air molecules cannot travel freely, and consequently, convection is not feasible. That is why we felt we utilized thermal insulation in choice to air.

Complete step-by-step solution:
Dry air is a lousy conductor, but heat can be carried into the air through convection and radiation.
Felt catches air. It is the air that is the natural thermal insulator. In houses, fiberglass has superseded it, which is more helpful at the same thing and does not deteriorate over time.
Vacuum is an excellent insulator, at least as distant as conduction runs. It is not possible in walls and ceilings, so trapped air insulators are utilized there. However, it is excellent in coffee mugs and chemistry dewars. Though the air is a lousy conductor of heat, it conveys more heat by convection.
In felt, the actual motion of air is discontinued by catching air in between its delicate fibers. Therefore, convection is suppressed. Due to it, the felt displays a better thermal insulator than air.
Felt might come as an astonishment because of its warm and fuzzy feeling. It holds the warm air out and enables the ice cubes to remain for a long time compared to another material. It also includes the cold air that the ice cube originates from, allowing it to chill itself off continuously. We provide them the most extended amount of survival time outside of the freezer by covering our ice cubes in felt.
The thermal conductivity of any substance is characteristic, which displays how express the shift of thermal energy within the substance is occurring. Diamond has the most considerable value of thermal conductivity.
Felt is an excellent material and a good insulator because it catches air and can capture much air. Felt is also suitable for the insulating temperature. Let us suppose, for example; we have an ice cube; felt holds the ice cube from converting a liquid because it acts as a natural insulator. By staying out of warm air, the ice cube can visit solid for a greater time.

Note: Felt might appear as a surprise because of its hot and fuzzy feeling, but this property is actually what presents it as an ideal choice for insulating ice. Felt holds ice from melting because it operates as a natural insulator. The thickness of wool permits it to protect the ice cubes as well as the felt.