A Conducting Shell around a Conducting Rod

AI Thread Summary
The discussion revolves around calculating the electric field and surface charge densities in a system consisting of an infinitely long conducting cylindrical rod with a positive charge density "lambda" and a surrounding conducting shell with a charge density of "-2 lambda." The radial electric field, E(r), between the rod and the shell is derived using Gauss's law, resulting in E(r) being proportional to "lambda" and inversely related to the distance r from the rod. The surface charge density on the inner surface of the shell, "fi - inner," is determined to be equal to "lambda," while the outer surface charge density, "fi - outer," is calculated based on the total charge of the shell. Outside the shell, the electric field E(r) is zero due to the shielding effect of the conducting shell. The problem highlights key concepts in electrostatics and the behavior of conductors in electric fields.
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Homework Statement



An infinitely long conducting cylindrical rod with a positive charge "lambda" per unit length is surrounded by a conducting cylindrical shell (which is also infinitely long) with a charge per unit length of "-2 lambda" and radius r1.

a) What is E(r) , the radial component of the electric field between the rod and cylindrical shell as a function of the distance r from the axis of the cylindrical rod?

Express your answer in terms of "lambda", r, and "epsilon" , the permittivity of free space.

b) What is "fi - inner" , the surface charge density (charge per unit area) on the inner surface of the conducting shell?

c) What is "fi - outer" , the surface charge density on the outside of the conducting shell? (Recall from the problem statement that the conducting shell has a total charge per unit length given by "-2 lambda" .)

d) What is the radial component of the electric field, E(r), outside the shell?


I have no idea how to solve this

Anyone that knows?
 

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http://www.physics.wisc.edu/undergrads/courses/spring08/202/hw2sols.pdf
 
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