# Charge 􀀓 is applied to a circular disk of ebonite of radius 􀀔 by rubbing it while it is rotating. Inthis way the surface charge density becomes proportional to the radial distance from thecenter. Show that the electric field strength on the axis of the disk at an axial distance ℎ fromthe center is 􀀖􀀗􀀘􀀙􀀌􀀚􀀛􀀜􀀝 􀀞􀀟􀀠 􀀜􀀡√􀀜􀀣􀀡􀀘􀀣􀀘 − 􀀥√􀀜􀀣􀀡􀀘􀀣􀀦 􀀧􀀨.

Rasanjana Weerarathne
11 Points
5 years ago

# Charge Q is applied to a circular disk of ebonite of radius a by rubbing it while it is rotating. in this way, the surface charge density becomes proportional to the radial distance from the center. Show that the electric field strength on the axis of the disk at an axial distance h from the center is

E=3Qh4πϵ0a3[lna+a2+h2h1a2+h2]an