Ohm's Law (in detail) Video Lecture | Physics for EmSAT Achieve

hello friends this video on current
electricity part 11 is brought to you by
exam feel calm no more fear from exam
please make sure that you have watched
all the videos till part 10 before going
ahead with part 11 oh it's time that we
study the most important law related to
current and that was Ohm's law
so Ohm's law is named after the
scientist own who found this law so
Ohm's law basically talks about how does
how is current dependent on the
potential difference that is applied
across a conductor let us suppose if you
have a conductor and you apply some
potential difference across the
conductor so how is the current which is
produced because of that potential
difference how does that current vary
with the potential difference which you
applied so this is an important law
which forms the basis of several other
concepts so this law states that current
flowing through a conductor is directly
proportional to the potential difference
applied between the ends of the
conductor that means if you increase the
potential difference between the ends of
a conductor the current flowing through
the conductor also increases similarly
if you decrease the potential difference
applied across the ends the current
through the conductor also decreases all
we can write it mathematically so this
can be written as let us suppose if I is
the current flowing through the
conductor then this is directly
proportional to V where V is the
potential difference applied between the
ends of the conductor let us suppose
this is a conductor and this is
connected to a battery so the current
which is flowing through this conductor
will be directly proportional to the
potential difference later suppose the
potential difference across this
conductor is V so the current which is
flowing through this conductor will be
directly proportional to V so this can
the proportionality can be converted to
a equality with the introduction of some
constant
now this constant was nothing but 1 by r
where r is the resistance of the circuit
now what is resistance we will study in
the next slide so this law became
popular as is equal to 1 by R into V or
V is equal to I I so this law became
popular with this expression V is equal
to I I so that is current and voltage
are directly proportional to each other
as the potential difference increases
current increases and vice versa so now
if you try to plot a graph what do you
see this expression is of the form of
how will the graph look like
can you guess let us suppose if you plot
a graph in such a way that you have
current along y-axis and voltage along
x-axis so how will your graph look like
so it is directly proportional so
therefore it has to be a straight line
because this expression is of the form y
is equal to MX plus C now we have taken
I along y axis now we know that the
equation for straight line is y is equal
to MX plus C now along Y axis we have
taken I so if you put I here and what is
X along x-axis we have taken V so what
will be this this will be 1 by R and
what will this EC will be is 0 so that
means M is the slope of the straight
line that means 1 by R represents the
slope of the straight line therefore the
graph would look somewhat like this so
this graph represents Ohm's law it shows
that voltage is directly proportional to
current and vice
and the slope of this line gives the
value of one bike R where R is the
resistance therefore V is equal to I R
is the standard expression or equation
representing Ohm's law where R is the
resistance of the conductor now we will
first study what is resistance because
only after we study resistance we will
actually know the concept of Ohm's law
because knowing Ohm's law without
knowing resistance is of no use like so
let us now thank you please visit exam
fee or comm to watch free educational
videos try three online tests get the
best quality study materials study from
the best tutors and mentors and much
more thank you once again