Conventional fuel : Petrol & Natural Gas - Sources of Energy, CBSE Class 10 Physics Video Lecture

hello friends this video on sources of
energy part 4 is brought to you by exam
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now talk about petroleum so right now I
mean you must be thinking that okay then
since coal has all the advantages of
being used as a fuel so coal is
obviously a very good source of energy
but right now I have not spoken about
the disadvantages of using these fossil
fuels so let me first discuss each of
these fossil fuels in detail one by one
so we completed coal now it's turn for
petroleum so let's discuss coal
petroleum and natural gas and then we
will look at the Dee's advantages as
well so when I talk of petroleum it is
formed by decomposition of diatoms deep
under the ground
so you got a new term here what are dye
atoms diatoms are nothing but these are
plant-like creatures which were present
in the oceans millions of years ago and
in during those period when fossil fuels
are formed at that time on it in the
oceans you had some tiny plants like
structures they were so small that you
can compare their size to the head of an
eagle
so you can imagine how tiny where they
so they were small creatures they were
plant-like creatures actually they have
the property similar to plants that they
could convert sunlight into stored
energy for example all of you must be
aware of photosynthesis right what is
photosynthesis or green plants which you
see around us they utilize the energy
from the Sun or they utilize the
sunlight in order to prepare their food
and that is how they get they convert
the sunlight into stored energy and they
store that energy within themselves
similarly these dye atoms also have this
property so there are small plant like
structures which were present in the
oceans which has the property of
converting sunlight into stored energy
so petroleum was formed by decomposition
of these guy atoms deep under the ground
so what happened when these diatoms diet
defend to the seafloor so here I have
represented I mean if you look at this
picture these represents die atoms so
even I have never seen a diet for myself
but this is how they looked like during
those years
right so when these diatoms died they
fell to the seafloor so normally they
were in the sea but once they died they
felt they went under the seafloor
so they went to the bottom of the sea
they got buried there and squeezed under
rocks so as I said I mean when something
goes to the bottom of them sea so
gradually rocks and other rocks and Kei
and everything will cover that those
things now gradually in due course of
time and at high temperature and
pressure they formed petroleum or oil
whatever you call it
so that means petroleum was formed by
decomposition of diatoms so when the
galleons were present in the oceans when
they died they fall to the seafloor now
once they were on the seafloor
they got covered with sand clay and
rocks it with due course of time they
got squeezed by the pressure from the
rocks they were buried and squeezed by
the rocks with and again over a period
of years under high temperature and
pressure petroleum was formed so now
again
now since petroleum was again formed
deep under the ground so how do we get
out how do we actually obtain petroleum
from there so the process of digging out
the petroleum from deep under the ground
is known as drilling like how we have
the term called mining with coal we
mined coal similarly we drill oil so it
is known as oil drilling so you would
have heard of several oil companies like
Indian oil or are making such companies
right so these oil companies wanting to
actually you have so many oil companies
around this Saudi Arabia Dubai and all I
mean that dodos part of the world so
there you have so many oil companies so
what do these oil companies do they
actually drill it through the earth to
find deposits of oil and natural gas so
again everywhere you will not have the
of petroleum so first you have to detect
the regional area where you have where
you actually have the deposits of oil so
they drill through the earth to find the
deposits of oil and natural gas oil is
then pumped from below by oil grains and
transported to pipelines or ship so this
is how I mean if you see this is a this
is how the transportation of oil takes
place so first it has to be drilled so
if you see if you look at this pictures
you can get some idea how things look
like so if you see here this is how the
drilling machine looked like with which
they drilled the earth and try to detect
the deposits of oil now once that is
detected using oil rings it is nothing
but an automatic equipment which helps
to drill or which helps to bring the oil
from deep under the ground to them
surface so that is how with the help of
oil rings the oil was pumped about and
then it was transported through
pipelines or through ship to different
parts of the world because you can have
these oil because it's only at certain
locations right but the need of the
petroleum as a source of energy is
everywhere so it has to be transported
to different places and that
transportation was done via pipelines or
ship so let us look at the third kind of
course and fuel that is natural gas
slacked what is natural gas it is in
gaseous form it is lighter than air it
is made up of meat theme so this M
please concentrate on the picture so a
nice a methane this is our structure of
methane lips left right ch4 so it is
made up of details and we can again it
has within consists of carbon and again
due to the presence of carbon it is such
a good source of energy
it is highly inflammable that means it
easily catches fire so it is inflammable
so the term inflammable actually means
something which catches fire very easily
so it can be very dangerous at times it
is usually found near petroleum
underground like just now I mentioned
right how petroleum was formed by the
composition of dye atoms now it is
saying that very well we have the
petroleum deposits
in the surroundings of the petroleum
deposits we often found natural gas
right so it is usually found near the
petroleum underground it is it is also
drilled out in the similar way I mean
when you drill out the oil that time
itself you pump out the natural gas as
well and again it is also transported
through pipelines it is order list order
list that means there is no smell not
since it doesn't have any smell so it is
difficult to detect the presence of
natural gas but at the same time as I
mentioned that since it is highly
inflammable so it can be very dangerous
at times but if it does not have any
smell and since it is in gaseous form so
you cannot see it as well right it is
not in in some solid form or liquid form
so if it doesn't have any smell it then
it becomes really really difficult to
detect its presence so what was done
when it was parked out after that it was
mixed with a chemical of strong order
before being sent to the pipelines
right so once you pump it out only after
pumping it out you will transport it
through the pipeline so before it was
sent to the pipeline it was mixed with a
chemical that chemical had a very strong
smell now once it is mixed with that
chemical now this natural gas also hired
a strong smell so now it became easy for
us to detect the presence of natural gas
so whenever you have that smell you can
detect the presence of natural gas and
then you can become cautious that's it
because you should not like a matchstick
near it because it will easily catch
fire so that is why you would have often
seen in your houses that your npg the
liquid petroleum gas which we use for
cooking purpose they often say that in
case of any leakage please keep all the
lights switched off and immediately
inform to the dealer so that they can
come and replace it right so sometimes
there might be some leakage with the
norm or some liquid somewhere so
whenever you take out and how do we Dowe
do you detect that leakage that leakage
is detected only by the smell so that
slay has become a very important aspect
which in short security otherwise what
happens if there is some leakage of the
natural gas then suppose if you switched
on the bulb in your kitchen
so the
the natural gas is present everywhere in
the room if it doesn't have any smell
you will not be able to detect it and it
will immediately catch fire as soon as
you switch on the bun right so even with
a smaller thing it will catch fire and
you can be extremely hazardous so that
is why it was mixed with this chemical
so that it has it gets a strong smell
which helps us to detect its presence
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