A sphere of radius 'r' is charged to a potential V. The outward pull per unit area of its surface is given by;...????
1 Answer
Feb 12, 2018
The pull per unit area is given as Electric field
Let charge on the sphere be
For an equally distributed charge Surface charge density
#sigma=Q/(4pir^2)#
Electric field at the surface can be found from Gauss's Law
#E=sigma/(epsilon_0)#
where#epsilon_0# is permittivity of free space
Rewrite above equation as
#sigma=epsilon_0E# .......(1)
We know that
#E = V/r# ........(2)
Pull per unit area
Using (1) and (2)
#P=V/rxx(Eepsilon_0)#
#=>P=V/rxx(V/repsilon_0)#
#=>P=epsilon_0V^2/r^2#
