I have a picture enclosed of the question, but I will type the question for claf
ID: 2144810 • Letter: I
Question
I have a picture enclosed of the question, but I will type the question for claficiation: A parallel plate capacitor has square plates of side A. The plates make an angle (x) with each other. For a small x, show that; C~ ((Eo*a^2/d )*(1-ax/2d)) that is, Eo= 8.85e-12 x=theta HINT: think of a bunch of small caps in parallel this involves integration total cap = sum of cap I will only give five stars to the person who answers this thoroughly, with explanation, reasoning, and clear steps. MUST be easy to read/interpret. thank you so much :)Explanation / Answer
consider a small cut dx
then this will have area = a* dx where a^2 = A
then distance = d + x tan theta
so dC = e0 a dx/( d + x tan theta)
since parallel we can just add these up
C = integral of dC
= integral of e0 a dx/( d + x tan theta) from 0 to a
= e0 a/d integral of dx/( 1 + x/d tan theta) from 0 to a
let u = x/d tan theta, then du = dx/d tan ttheta
and dx = d du/tan(theta)
small angle so tantheta = theta
= e0 a/d * d/theta integral of du/(1 + u) from 0 to a/d theta
= e0 a/theta * ln( 1 + u) from 0 to a/d theta
= e0 a/theta * ln ( 1 + a theta/d)
but since theta is small
ln(1 + a theta/d) = a theta/d - 1/2 (a theta/d)^2
so C = e0 a/theta (a theta/d - 1/2 (a theta/d)^2 )
c = e0 a^2/d *1 - 1/2 a theta/d)
thus shown
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.