Formula confusion for magnetic field inside capacitor

[Suyash Singh]

Homework Statement

Uploaded question(the formula in c part)
And can you tell me in which all cases that formula is used.

Homework Equations

Just want to know where the formula in c part has come from.

The Attempt at a Solution

Sum of magnetic fields due to circular plates calculated and added but that seems to be wrong method here.
I just need some kind of site to study that formula.
Thankyou

 

[berkeman]

UPLOAD didn't seem to work. What file type is it?

 

[Suyash Singh]

UPLOAD didn't seem to work. What file type is it?

.png

 

[berkeman]

I think that file type is supported, but I'm not sure. Are you on a laptop or a phone?

 

[Ray Vickson]

Homework Statement

Uploaded question(the formula in c part)
And can you tell me in which all cases that formula is used.

Homework Equations

Just want to know where the formula in c part has come from.

The Attempt at a Solution

Sum of magnetic fields due to circular plates calculated and added but that seems to be wrong method here.
I just need some kind of site to study that formula.
Thankyou

I can see the image but it is virtually unreadable.

Please go back to the basic PF standard and just type out the expression you are interested in. Most helpers will not even bother to look at an uploaded image, and when it is unreadable they will just go away, unwilling to help.

 

[TJGilb]

Just want to know where the formula in c part has come from.

It comes from Maxwell's addition to Ampere's Law. You can use that to solve for the magnetic field in between a capacitor, but they just did the work for you. Here's a link to the hyperphysic's page on Ampere's Law http://hyperphysics.phy-astr.gsu.edu/hbase/electric/maxeq2.html#c4

The magnetic field is the result of the changing electric field as the capacitor plates charge. Also, actually solving for formulas like that is typically an upper-ish level undergraduate E&M course task (requiring integral calculus, curl, etc.) so don't worry about it too much if you're not there yet.

 

[Suyash Singh]

thankyou.
I will type out the question next time.