The discussion revolves around the concept of electric fields within conductors, particularly focusing on scenarios involving hollow conducting cylinders and charged wires. Participants explore the implications of Gauss's law and the behavior of electric fields in the presence of charges inside and outside conductors.
The conversation is ongoing, with participants raising multiple questions about the nature of electric fields in different configurations. Some have provided insights into the relationship between surface charge density and induced charges, while others seek clarification on specific terms and concepts.
There is mention of a quiz deadline, indicating a sense of urgency in understanding the material. Participants also reference specific problems from external sources, which may introduce additional complexity to the discussion.
What does sigma represent? The surface charge on the outside of the cylinder? If so, then sigma/epsilon is correct.madah12 said:ok another question in this case of a wire inside a hollow conduction cylinder is E at the surface of the cylinder equal only to sigma/epsilon naught or is it (lamba * l + sigma *A)=E*A? because the book says the field on the surface of the cylinder is sigma/epsilon
That's right. And if the cylinder has no net charge of its own, the field outside its surface will equal that of the line charge.madah12 said:yes sigma is the outer surface density ,so I understand so you are saying that because on the inner surface there is q induced that is equal and opposite to the one of the wire?
so even outside the surface of the cylinder Q only equals sigma outer *outer surface area?
In that problem statement, sigma represents the total charge per unit area on the cylinder, not just the charge on its outer surface. (The problem is confusingly worded.) Think of sigma as the charge on the outer surface before the line charge is introduced. Once you include the induced charge due to the line charge, then the outer surface will have zero sigma.madah12 said:http://physics.kuniv.edu.kw/phys102/08-09-S-ms1.pdf
look at number 5 how can the field be zero if Q=sigma *a
I imagine that means the total charge per unit length. (As opposed to the surface charge, which is per unit area.)madah12 said:so sometimes they say the linear charge of a cylinder do you know what that means?