Charge to mass ratio of electron - Structure of Atom Video Lecture - Class 11

hello friends this video structure of
atom part 4 is brought you by exam 3
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watching this video please make sure
that you have watched part 1 2 part 3
so if you see now by this time we knew
that there is something called electron
which is a negative charge but what is
the charge of electron what is the mass
of electron those things were totally
oblivion we didn't know what is the mask
what is the charge at that point of time
please note what I'm teaching you now is
nothing but a history of chemistry
history of chemistry so I am talking
about this thing in the old era where
the charge of the electron was not known
so in that case what we did was this guy
in 1897 till that time the charge of
electron was not known this guy Thomson
what he did was he found charge to mass
ratio and how I found was he used this
cathode ray tube and then he applied
once magnetic field and once electric
field right so you see once he applied
magnetic field the electrons let's
suppose strike here then you apply
electric field and the electrons strike
here instead of going straight and then
without electric field it goes to B then
what did it was he somehow balance the
electric field magnetic field in such a
way that both cancel each other and the
electrons strike this to the chi'lan sir
and with that value of electric field
magnetic field he had a lot of
calculations which we will not go deep
into it but with that calculation with
that experiment he found that Charles to
mass ratio of electron is 1.75 82 0 into
10 to the power 11 Coulomb per kg this
was the charge to mass ratio that was
found by JJ Thompson by using the
explain
hope you understand what I did so
initially the electron went and strike
at B he applied electric field it went
at a hip like the
the electric field is gone now he
applied magnetic field only the
electrons hit at C then he applied both
electric field mine in the field you see
this is electric field and this is
magnetic field right he applied both
electric and magnetic field and he
balanced the survey that would
cancellations around the electron hitter
there were the point B and then with
that calculation he found ebuy emanation
so the observation was the amount of
deviation the amount of deviation which
you see example instead of V it can go
to a and CV this amount of deviation it
can go a or a - this amount of deviation
of the particle oil in magnetic field or
electric field that depends on the
magnitude of the negative charge it's
directly proportional more the charge
more in the division okay also mass
lighter the mass go to the deflection
now also if you see it is a small ball
if you had it goes to a large distance
the big log if it goes to smaller this's
similar thing here also if they elect
the the particle is big the deflection
will be less if the particle is small
deflection will be more the strength of
electric and magnetic field so for the
same setup if you increase the electric
field the deflection be more the same
sector if we increase in I antiquated
African move also so he observed all
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