Advertisements
Advertisements
प्रश्न
Draw a labelled diagram of a thermo flask. Explain how the transfer of heat by conduction, convection and radiation is reduced to a minimum in it.
Advertisements
उत्तर
Heat transfer is minimised because of:
(1) The vacuum between the two walls, rubber, glass, cork and air do not allow the loss of heat by conduction.
(2) Cork in the neck of flask and the cup over it prevent loss of heat by convection.
(3) Heat cannot be lost by conduction or convection because of vacuum between the two walls.
(4) Heat loss is also minimised by radiation, by making outer surface of inner wall and inner surface of outer wall silvered. The inner wall is a BAD RADIATOR and the outer wall is a GOOD REFLECTOR of radiation.
APPEARS IN
संबंधित प्रश्न
While deciding the unit for heat, which temperature interval is chosen? Why?
What will absorb heat?
Steel spoon
What will absorb heat?
Glass vessel
What will absorb heat?
Wooden spoon
Which of the following substances will absorb more heat energy?
We reduce the heat by adding ______ while preparing fruit juice.
In the arrangements A and B shown in the following figure, pins P and Q are fixed to a metal loop and an iron rod with the help of wax. In which case are both the pins likely to fall at different times? Explain.
In which of the following, chemical energy is converted into heat energy?
Warm air is ______.
Heat gained by a body depends upon which factors?
