Question

Describe the process of convection of heat? Draw a neat labelled diagram of a thermos flask. How does it prevent transfer of heat by conduction, convection and radiation? How sea breeze and land breeze are set up in different paragraph and should be short?

Answer 1

when liquids and gases are heated the molecules become warm and less dense they expand and rise the molecules from the colder portions of substance flow downwards to take place of the warm molecules they in turn rise when they get warm this continues process is called convection.
heat loss due to conduction is prevented because glass is poor conductor of heat conduction cannot take place in vacuum because it needs medium the stopper and the vacuum prevents heat loss due to Convection the highly polished Silver wall prevent heat loss due to radiation

Answer 2

Answer:

A thermos flask is a household item that is used to keep things warm or cold

for a long time. It consists of a double- walled vacuum flask. A vacuum flask is a

bottle made of glass or metal with hollow walls. The narrow region between

the inner and outer wall is evacuated of air and sealed together, at their necks

or at the bottom. The walls are silvered. The vessel is put in a metallic case and

is separated from it by cork or plastic supports. This prevents the glass vessel

from breaking. The mouth of the vessel is closed by a stopper made of an

insulating material like cork or plastic.

The vacuum between the two glass walls of the thermos flask

considerably reduces the flow of heat by conduction and convection. This is

because both conduction and convection need molecules of a medium for

transfer of heat. The silvered surfaces reflect the heat back, thus, reducing

radiation. hope it helps it's not frome Google . sorry I don't have the pic .