# In a spherical capacitor with plate radii a and b, the PD between them is V. The electric field between the platesnat a radial distance r from the centre is?

Arun Kumar IIT Delhi
8 years ago
Hi Mostafijur,

Let the inner sphere has a charge +Q
outer sphere -Q
then
between the sphere we have
$\\E.4\pi r^2=Q/\epsilon_{0} \\=>E=Q/4\pi r^2\epsilon_{0} \\=>V=Q/4\pi \epsilon_{0}(1/a-1/b) \\=>E=V(1/a-1/b)/r^2$

Thanks & Regards

Arun Kumar

IIT Delhi

Yash Chourasiya
2 years ago
Hello Student

Let potential of the plate of radius a
Q = CV
V = Q/C
E = KQ/r2
V = KQ(b−a)/ab
Q = Vab/K(b−a)
E = (K/r2)(Vab/K(b−a)) = abV/r2(b−a)