Gauss law and Application of Gauss
law
,I. New and central
Electric Field
electrostatics is based
Concept ,
all
theory in on this idea .
2 It from
very different
.
is mechanics View .
3.
Hauge and abstract concept ,
but
necessary
.
Need for the Field .
Big Void in Newtonian View .
The ideas in Newtonian Picture is
key
lit Action at a distance and without medium .
Iii ) Force ✗
distance
liiil Force acts
along
the line
joining two
objects .
Action at a distance
theory .
forces
Electric and
magnetic ,
like
gravity .
are
long range forces ; no contact is
required to exerta force between two
charged Particles Therese Comes
.
question that if A- and apart and
B two
charges 1000
light Years
a are
Coulomb's law tells
they us exert force on each other ,
and now if
the force
• ' ' '
charge starts moving charge
A Does this
change
on B will .
change happen instantly ? Or is there delay to transmit
will be some
the force ?
Newton 's law and Coulomb's law both are independent of time
from Prospective of Newtonian
Physics the
so the answer will be
instantly But scientists found this
troubling
many
.
.
Or steel Performed an experiment that
magnetic needle experiences
a force when it is Placed current and
near a
carrying wire ,
also if replace the current
we
carrying
wire with a
charge particle
, the of force depends
magnitude the on the
velocity of charge .
The direction of the force is Perpendicular to the line
joining them .
This
theory
was not also explained with Newtonian , so we need a
new
way to explain this ,
and this is the birth of field theory .
Michel
Faraday .
When we Place a bar
magnet on a surface and sprinkle some
iron
filings on it the iron
filings forms some Pattern around it .
found this the space
Michel
Faraday interesting he suggested
that
around bar filled of magnetic influence
magnet is with some kind .
The
magnet itself somehow alters the space around it and
by this
mechanism
long range force is exerted .
B
! !
!!
In Newtonian view .
'
'
! ! i
directly ;;
:
.
A
A- exerts a force : :
: : .
.
" ; "
on B. "
:÷÷÷;j;
÷
,
B In
Faraday 's view
i i.
.
;
If
.
.
.
it :
'
alters the space
.
;
:
iii. :
.
C I
,
i.
around it and Particle
'
B' responds to this altered space .
Faraday with some simple experiments and Pictorial thoughts gives the idea of
the field But without mathematics scientist did
seriously
. not accept it .
After few years Maxwell use the idea of the field a
give mathematical
description of field .