cylindrical capacitor Definition and 25 Threads

So my idea was to separate the capacitor into two individual ones, one of length ##l - a## filled with a vacuum and one of length ##a## filled with the glass tube. The capacitances then are $$ C_0 = \frac{2 \pi \varepsilon_0 (l-a)}{\displaystyle \ln\left( \frac{r_2}{r_1} \right)} $$ for the...

we know that flux is equal to the area integral of electric field dotted with dA and we can set this equal to charge enclosed divided by epsilon naught. Thus, in this case, the integral simplifies to E * A = (q_enclosed)/(ε_naught) when we choose a cylindrical gaussian surface with radius of r...

I don't understand how they got from the previous step to the next step of the derivation circled in red: Many thanks!

Homework Statement There is a capacitor (llenght ##L##) made of a conductor (cylinder of radius ##R_1##) and a cylindrical surface (radius ##R_2##). It is charged with a potential ##V_0##, then it is isolated. (There is vacuum between ##R_1## and ##R_2##) Now we insert a cylindrical...

Homework Statement In a lab experiment we measured the potential at different points within a cylindrical capacitor electric field modeling plate thing (apparently that's the best I could do to translate that into English). The positive electrode was connected in the middle and the negative...

Homework Statement Normally this style of question wouldn't be too bad, however the 2 different parts confused me. Surely once set to a potential V, it would stay at that potential - it doesn't need to stay connected How are the 2 parts any different from each other?

Homework Statement We have two coaxial cylinders with radius r0 and r1. The space between the two cylinders is completely coverd with two coaxial isolation layers with relative dielectric constants ε1 and ε2, ε1 is for the inner layer. Calculate the thickness of the inner layer such that the...

So far I have learned about Coulomb's law, the electric field, gauss's law, the electric potential and now capacitance. I feel that although I "know of" these topics, I don't actually "flow with them". Ignoring the math for a second; I want to form an understanding. And I think calculating the...

Homework Statement Consider a long cylindrical coaxial capacitor with an inner conductor of radius a, and outer conductor of radius b, and a dielectric with a relative electric permittivity or dielectric ε(r), varying with the cylindrical radius. The capacitor is charged to the voltage V...

Homework Statement The outer conductor (radius b, length l) of a long cylindrical capacitor is earthed. The inner conductor (radius a, length l) is hollow, insulated and uncharged. A sphere of radius R is charged to a potential V far from any other bodies and is inserted inside the inner...

Homework Statement Calculate the electric field of a cylindrical capacitor comprised of a smaller cylindrical conductor of radius ##a## enclosed within a larger cylindrical conductor of radius ##b## where ##b>a##. The smaller cylinder has charge ##+Q## and the larger cylinder has charge...

Homework Statement A very long question. First let's solve the case for E-field between outer and inner capacitor. Homework Equations The Attempt at a Solution Since there is no charge between the 2 capacitors, the charge density is zero. By Gauss's law, the integral is zero...

Homework Statement You have a co-axial cylindrical capacitor placed in vacuum. The two co-axial cylinder tubes are made of copper. The outside tube radius a1 and inside tube radius a2, with overlapping length L; both tubes have a thickness of t. Say, the capacitor was designed to withstand 5...

Homework Statement Find the potential of a cylindrical capacitor Radius of both cylinder plates, x and y where x<y Height of the cylinder: h Charge on the plates: qHomework Equations E = \frac{q}{A\epsilon_0} = \frac{q}{2\pi r h \epsilon_0} \Delta V = \frac{\Delta U}{q} = - \int_a^b E drThe...

Homework Statement A coaxial cable used in a transmission line has an inner radius of 0.15 mm and an outer radius of 0.65 mm. Calculate the capacitance per meter for the cable. Assume that the space between the conductors is filled with polystyrene. (Also assume that the outer conductor is...

Homework Statement I must calculate the capacitance of the following capacitor : A cylindrical capacitor made of 2 shells (not sure if shell is the right word in English. Made of 2 cylinders maybe), one of radius a and the other of radius b>a. It has a length of L. We introduce entirely...

Homework Statement Hey guys, My prof asked us to find the radius of a cylinder within a cylindrical capacitor with 2 radii a and b. I know we use the Capacitance formula for a cylinder but I can't seem to get pass the q that shows up when I plug it into the 1/2 c*V^2 EDIT: He wants us to find...

Homework Statement A cylindrical air capacitor with a length of 12.2 m stores an amount of energy equal to 3.00E-8 J when the potential difference between the conductors is 4 V. Calculate the magnitude of the charge on each conductor. Homework Equations...

Hi All, from this page (Cylindrical Capacitor) => http://www.phys.uri.edu/~gerhard/PHY204/tsl105.pdf What happens when L is <= b? Does the computation change? and from this page http://www.physics.umd.edu/perg/abp/TPProbs/Problems/E/E52.htm The capacitor is simplified to a plane...

1. How do we calculate the electric field of a Coaxial Cylindrical Capacitor?? That is one question, the other is: Is the field strength E the same at all locations of a uniform electric field at any point between the plates or electrodes of a parallel plate capacitor, and or a cylindircal...

Homework Statement You are asked to construct a capacitor having a capacitance near 1 nF and a breakdown potential in excess of 13000 V. You think of using the sides of a tall plastic drinking glass as a dielectric (with a dielectric constant 5.2 and dielectric strength 12 kV/mm), lining the...

Why is the theoretical capacitance for a cylindrical capacitor (given here http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capcyl.html) equal to the value measured on the outer shell with the inner grounded using a L-C meter? I'm stuck.

A capacitor consists of two thin infinite concentric cylinderss with inner and outer radii a and b. If the outer cylinder has radius 10mm and the breakdown electric field of air is 3V per micrometre, what radius should be choosen for the inner cylinder in order to maximum the potential diffence...

I would like to know about fine tuning of an airplane Fuel Gauging probe. It is basically a cylindrical capacitor made of an inner composite tube of about 0.5 inch diameter and an outer composite tube of about 1 inch diameter. The length of the tubes varies from about 3 inches to 8 inches. The...

For some reason, I am having a lot of difficulty finding the electric field between two co-axial cylinders. In fact, I pretty much know that it should be: \frac{Q}{2\pi \epsilon _0 Lr} Where Q and -Q are the charges on the two cylinders, L is the length of the cylinders, and r is the...