A nonconducting spherical shell problem

Click For Summary
SUMMARY

The discussion focuses on determining the constant A for a nonconducting spherical shell with inner radius a = 2.00 cm and outer radius b = 2.40 cm, which has a charge density p = A/r. The goal is to ensure a uniform electric field within the shell, where a ≤ r ≤ b. The established solution indicates that A must equal 1.79 × 10-11 C/m to achieve this uniformity. The user initially attempted to apply the equation E = kq/r2 but struggled with the variable nature of r within the specified range.

PREREQUISITES
  • Understanding of electrostatics, specifically Gauss's Law
  • Familiarity with electric field concepts and charge distributions
  • Knowledge of spherical coordinates and their applications in physics
  • Basic proficiency in calculus for integrating charge density functions
NEXT STEPS
  • Study Gauss's Law and its application to spherical charge distributions
  • Learn how to derive electric fields from charge density functions
  • Explore the concept of uniform electric fields in different geometries
  • Investigate the implications of variable charge densities on electric field calculations
USEFUL FOR

Physics students, electrical engineers, and anyone interested in electrostatics and electric field analysis will benefit from this discussion.

noppawit
Messages
27
Reaction score
0
A nonconducting spherical shell of inner radius a=2.00 cm and outer radius b = 2.40 cm has (withing its thickness) a positive charge density p = A/r, where A is a constant and r is the distance from the center of the shell. In addition, a small ball of charge q=45.0 fC is located at that center. What value should A have if the electric field in the shell (a[tex]\leq[/tex]r[tex]\leq[/tex]b) is to be uniform?

I know the answer that A value is 1.79[tex]\times[/tex]10-11. The problem is I don't know how to solve it. I don't even know which equation I should use. I tried to start with E = kq/r2, but what is the value of r. It is not specified where should I calculate.

Please help.
Thank you.
 
Physics news on Phys.org
r can have any value between a and b. It is a variable, with no specific value.

Do you know what charge the "q" refers to in your equation for E?
 

Similar threads

Replies
5
Views
1K
Replies
4
Views
2K
Replies
1
Views
972
  • · Replies 2 ·
Replies
2
Views
2K
Replies
9
Views
2K
  • · Replies 14 ·
Replies
14
Views
13K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 19 ·
Replies
19
Views
4K
  • · Replies 9 ·
Replies
9
Views
3K