Register to reply

Electric field strength and electric potential in a sphere

by Kurokari
Tags: electric, field, potential, sphere, strength
Share this thread:
Mar2-12, 09:30 PM
P: 35
Given a solid metal sphere where all the positive charges are distributed evenly on the surface of the metal sphere.

My textbook says that there is no electric field strength in the middle of the metal sphere because the charge = 0. However, my understanding is that wouldn't the center of the metal sphere be under the influence of the charges on the metal sphere surface, but because of the shape, all the electric field strength acts in opposite direction thus cancelling each other out.

The second question is, when there is no electric field strength, the electric potential is zero , that would mean that potential is either maximum or minimum given, E = - dV/dr . So why is it maximum in the sphere, why not minimum? What is that explanation?
Phys.Org News Partner Physics news on
Physicists unlock nature of high-temperature superconductivity
Serial time-encoded amplified microscopy for ultrafast imaging based on multi-wavelength laser
Measuring the smallest magnets: Physicists measured magnetic interactions between single electrons
Mar2-12, 09:48 PM
P: 409
Hi Kurokari,

1. You're right. Zero charge at a point doesn't mean zero filed at that point.

2. Zero field means a constant potential. The sphere has a constant potential. The same potential for the interior. I assume you are aware of the formula for the potential of a charged sphere.

Register to reply

Related Discussions
Calculating Electric Field Strength using Electric Potential? Introductory Physics Homework 9
Electric Field strength of sphere Introductory Physics Homework 1
Question about Electric Field Strength and Electric Potential Introductory Physics Homework 1
Find the electric field strength inside a solid sphere. Advanced Physics Homework 8
Electric Potential and Electric Field Strength Introductory Physics Homework 7