Answer:
The demand
of energy is increased due to the industrialisation all over the world.
The
environmental consequences of increasing demand for energy are as follows
(i) Use of
fossil fuels is increasing air pollution which is not good for our health.
(ii) Air
pollution is causing much damage to the ecosystem.
(iii) Greenhouse
effect has resulted in global warming which is manifesting itself in strange
changes in the weather pattern around the world.
(iv) Too
much exploitation of fossil fuels is going to create a situation when there
would be not fossil fuel. (2)
The steps
to reduce energy consumption
(i) Judicious
use of energy is the only way.
(ii) Use
public transport instead of private modes of transport.
(iii) Use
bicycle whenever possible.
(iv) Walk
for short distance commute.
(v) Avoid
unnecessary use of modern gadgets which consume lot of energy.
(vi) Use
appliances that run using non-conventional sources like solar cooker
etc. (3)
Or
Solar
Water Heater It is a device which heats the water using solar
energy. (1)
Principle
(i) A black
surface absorbs more heat as compared to white or reflecting surface under
identical conditions.
(ii)
Greenhouse effect is provided by glass lid. (1)
Structure
It consists
of an insulated box which is painted black from inside having a coiled black
chrome painted copper pipe.
The box is
covered with glass lid so as to prevent heat loss by convection and radiation.
The two ends of the copper pipe of solar water heater are joined to the water
storage tank which is insulated to prevent heat loss. (1)
Working
·
The copper pipe warms up due to solar radiations incident on it.
·
The glass lid on the box provides the greenhouse effect to
optimise the heating.
·
The water flowing through the tube gets heated by absorbing solar
energy.
·
The hot water becomes lighter which flows up into the tank and
heavier cold water from same tank enters into the copper pipe.
·
The circulation of water from the tank through the pipe and back
to the same tank continues automatically, due to density difference between
cold and hot water. (2)
You need to login to perform this action.
You will be redirected in
3 sec
