Charge in a spherical conducting shell

[Markv]

Homework Statement

There's a conducting spherical shell with Q = q₂ and V =100v and outter radius R

Homework Equations

V=k*Q/R

The Attempt at a Solution

First I calculate the E field using Gauss law, and I get E=q₂/4*Pi*E₀*r

Integrating the E field to get the potential V y get:

V = q₂/4*pi*E₀*R = 100

And there I get the value of q₂

 

[kuruman]

1. What is the question that the problem poses?
2. What can we do for you?

 

[Markv]

Sorry this is the first time I open a thread and I might haven't been too concise.

Im asked to find the charge in the sphere knowing the inner radius = 0.15m and the outter radius = 0.2

The result I get is 2.22 exp -9 when the correct answer according to my assignment should be 1.67 exp -9 so i don't know where the mistake is.

 

[kuruman]

We can help you find your mistake if you can show us exactly what formula you used and what numbers you put in it.