Electric Potential of an insulating washer

[jg370]

Hi, I have find an expression for the Electric Potential of a uniformly charged insulating washer of innner radius a and outer radius b at a point P located a distance z from the washer along the symmetry axis perpendicular to the washer.

I have come up wiht the idea that this problem might be best solved by substracting the Electric Potential (Va) for a disk of radius a from the Electric Potential (Vb) for a disk of radius b.

Or do you see another method?

thank you for your help,

JG

 

[turin]

Your method looks good to me.

 

[M98Ranger]

Thank you for your question, JG. Your approach of subtracting the electric potentials of two disks is a valid method for finding the electric potential of an insulating washer. This is known as the method of images, where we use the electric potential of a known system to solve for the potential of a more complex system.

Another approach that you could use is the superposition principle. This principle states that the total electric potential at a point due to multiple point charges is equal to the sum of the individual potentials at that point. In this case, you could consider the washer as a collection of infinitely small point charges, and use the electric potential formula for a point charge to find the total potential at point P. This method would require some integration, but it is another valid approach to solving this problem.

Ultimately, both methods should give you the same result. It is up to you to choose the method that you are most comfortable with and that aligns with the tools and concepts you have learned in your course. I hope this helps, and good luck with your problem!