Problem 3: A. Two Wo very thin spherical shells (Fig. A), are arranged concentri

Question

Problem 3: A. Two Wo very thin spherical shells (Fig. A), are arranged concentrically. The Inner shell has radius a-3 mm, the outer, radius b-9 mm. Half the space between the shells is filled with air while the other half is filled with water. 1 he air permittivity between the shells is eo. The water permittivity between the shelis is e-40. Calculate the capacitance of the device (i.c. the capacitance between the two shells) Fig. A Fig. B 4?? a b 2b tz In Cl water Clear all;clci 8part a a 3e-3;b-9e-3; ep80-8.85;%in pico eps-4*epso; %Find Cair %Find CH20 C air- c water- c-c air+C water B. In Fig. B, calculate the self-inductance L of 10 cm of coaxial cable with 0.8 mm and b 4 mm, filled with material for which ?-30; a clear all; clc; a-0.8e-3; b-4e-3; L-10e-2; mu 0-0.4*pi; %in milli mur-30; %in mH

Explanation / Answer

Part A code:

clear all;
clc;
%%part a%%
a=3e-3; b=9e-3;
eps0=8.85e-12;
eps=4*eps0;
C_air= (4*pi*eps0)/((1/a)-(1/b))
C_water= (4*pi*eps)/((1/a)-(1/b))
C=C_air+ C_water

Part A output:

C_air =

   5.0046e-13

C_water =

   2.0018e-12

C =

   2.5023e-12

Part B code:

clear all;
clc;
%%part b%%
a=0.8e-3; b=4e-3; l=10e-2;
mu=0.4*pi*1e-6;
mur=30;
Inductance_L=((mu*mur*l)/(2*pi))*log(b/a)

part B output:

Inductance_L =

   9.6566e-07 or 0.96566e-0.6 H

NOTE: %% there is a small mistake in code for part B. mu0 is in micro units not in milli units thus why the

final answer is in micro H not in milli H..%%

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.