AC Voltage Applied to a Series LCR Circuit: Part 2 (Impedance) Video Lecture - JEE

hello friends this video on alternating
currents part 14 is brought to you by
exam feel calm no more fear from exam
please make sure that you have watched
all the videos turn part 13 before going
ahead with part 14 the point which we
are I wanted to discuss is that
impedance in an LCR circuit now how we
the way we talked about resistance in
case of a resistive circuit inductive
kappa inductive reactance for an
inductive circuit and capacitive
reactance for a capacitor circuit
similarly the resistance of an LCR
circuit is known as impedance so
impedance is a value which is the net
resistance offered by LCR circuit that
means it will include the resistance
offered by the resistor the inductor as
well as the capacitor so it is the
resistance associated with a series LCR
circuit so it is denoted by a capital Z
SI unit is as usual home because they
are end of the day they are all
resistances so the SI unit and the
dimensions will be same as that of our
resistance so when I talk about
impedance I will tell you about I mean
how do we express impedance so impedance
is basically given as Z is equal to so Z
is given by root over R square plus XC
minus X and whole square so you might be
wondering from where did I get such a
big formula of impedance we will talk
about impedance in detail later but for
now I am introducing impedance is that
because when I solve the equation which
I showed you in the previous slide you
will we will use this Z right so Z is
related to the resistance capacitive
reactance and inductive reactance in
this form so we have something called
impedance diagram that is nothing but a
right angle
triangle whose hypotenuse is this
represented as the impedance base is the
resistance and the height or the
perpendicular is the difference of
capacitive reactance and inductive
reactance so from where did we get this
that we will talk about in one of the
later side slides so for now you should
just know that Z is the impedance of LCR
circuit Z is given by root over R square
plus XC minus xn whole square because
from this triangle it is easy to see
that if you apply Pythagoras theorem
your Z squared applying Pythagoras
theorem Z square becomes equal to R
square plus XC minus X and whole square
right so from there itself you can say
that Z is equal to R square plus XC
minus X L whole square right so this is
your Z and also we define this angle
that is the angle between the net
impedance and the resistance as fine so
we often see that tan Phi is equal to XC
minus X n divided by R now what is the
significance of this angle Phi that we
will study later so I will come back to
all these things so as of now I just
introduced introduced impedance so that
you do not feel difficulty why we solve
the differential equation which I
mentioned in the previous slide thank
you please visit exam few comm to watch
free educational videos try 3 online
tests get the best quality study
materials study from the best tutors and
mentors and much more thank you once
again