Electricity and Magnetism Question

[Ave Kar]

I have a couple of questions in E&M.

a)Can anyone tell me what a coaxial resistor and a coaxial capacitor looks like? (Approx Diagram) Because I am not sure which equations apply to them since I am not sure what they look like.
b)How do I find a self energy of a charged sphere? Split it into 2 parts and bring it together? Not sure on this one, if someone can help, thnx.

 

[interested_learner]

b) Do you mean how do you measure (in the lab) the energy in a charged sphere?

Or do you mean how do you calculate the energy in a charged sphere?

There is a good discussion on calculating the energy of a charged sphere in Feynman Lectures Volume II chapter 8-1.

a) Just do a Google sreach for the coaxial caps and resistors. You can find the complete specs from most vendors.

 

[m2003]

a) A coaxial resistor and capacitor are both cylindrical in shape and consist of two conductive cylinders separated by a dielectric material. In a coaxial resistor, the inner cylinder is the resistor material while the outer cylinder acts as a shield. In a coaxial capacitor, the inner cylinder is one plate of the capacitor while the outer cylinder is the other plate.

b) To find the self energy of a charged sphere, you can use the equation U = Q^2 / (8πε0r), where U is the self energy, Q is the charge on the sphere, ε0 is the permittivity of free space, and r is the radius of the sphere. To split the sphere into two parts, you can imagine cutting it in half and treating each half as a separate charged sphere. Then, using the equation above, you can find the self energy of each half and add them together to get the total self energy of the original sphere. Bringing the two halves together will not change the total self energy, as the electric potential energy is a conservative force.