Σ free on two dielectric spherical surfaces

AI Thread Summary
The discussion focuses on calculating the electric field and dipole moment for a system involving two dielectric spherical surfaces. The user has determined the total dipole moment but is uncertain about the electric field, particularly for regions inside the sphere (r<R) and outside (r>2R). They believe their expression for the electric field in the region r>2R is correct but are questioning their findings for r<R due to inconsistencies with previous problems. There is confusion regarding the surface charge densities, specifically σ1 and σ2, with σ1 being interpreted as 4σcosθ and uncertainty surrounding σ2. The user seeks clarification on the analytic expressions for the surface charge densities to resolve their doubts.
guyvsdcsniper
Messages
264
Reaction score
37
Homework Statement
σ 1 and σ 2 are pasted to 2 spherical dielectric surfaces w/ radius r and 2R

2.)Calc. E when r<R and r>2R
3.)Calc E when R<r<2R
Relevant Equations
Dipole Potential
I have found the total dipole moment of for this problem but am having trouble finding the electric field.

I believe my electric field when r>2R ( I mistakenly wrote it as r<2R on my work, but it is the E with a coefficient of 2/3) is correct as it fits the equation:
Screen Shot 2022-04-18 at 10.06.02 PM.png
.
I don't believe this formula applies inside the sphere though, just based off experience with other problems because with other problems, I don't get that 2cosθ +sinθ. Which is making me second guess my E for r<R. Mathematically it seems correct but I feel I may be missing something fundamental.

Do my E.F. for r<R and r>2R seem correct?
nxt73qV.png
Screen Shot 2022-04-18 at 10.02.08 PM.png
 
Physics news on Phys.org
Please show the complete statement of the problem as given to you. Specifically, do you have analytic expressions for ##\sigma_1## and ##\sigma_2##? The figure shows σ1=4σcosθ on the inner sphere which I can interpret as ##\sigma_1=4\sigma \cos\!\theta## but then I see on the outer sphere σ2=σdos0 which I don't know how to interpret and which reminds of covfefe.
 
  • Like
Likes SammyS
Thread closed temporarily for Moderation...
 
Thread 'Minimum mass of a block'
Here we know that if block B is going to move up or just be at the verge of moving up ##Mg \sin \theta ## will act downwards and maximum static friction will act downwards ## \mu Mg \cos \theta ## Now what im confused by is how will we know " how quickly" block B reaches its maximum static friction value without any numbers, the suggested solution says that when block A is at its maximum extension, then block B will start to move up but with a certain set of values couldn't block A reach...
TL;DR Summary: Find Electric field due to charges between 2 parallel infinite planes using Gauss law at any point Here's the diagram. We have a uniform p (rho) density of charges between 2 infinite planes in the cartesian coordinates system. I used a cube of thickness a that spans from z=-a/2 to z=a/2 as a Gaussian surface, each side of the cube has area A. I know that the field depends only on z since there is translational invariance in x and y directions because the planes are...
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'
Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is(Figure 2): F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
Back
Top