Capacitance Definition and 874 Threads

Could anyone help me to find out a book which has detailed explanation(derivations) for the capacitance, inductance of a mictropstrip line. It would be helpful if the book has detailed discusions on fringing fields,(effective width of the ground plane) effective permitivty etc. I have tried...

Homework Statement A spherical conducting shell of radius 0.1 m has a free charge of -2 μC. It is surrounded by a concentric spherical conducting shell of radius 0.12 m carrying a free charge of -2 μC. Between the shells is a dielectric material of dielectric constant 10 εo. If the dielectric...

Homework Statement Show that for two arbitrary conductors the coefficients of capacitance C12 and C21 are always equal. Hint: Consider a two-conductor system in which the two conductors have been charged so that their potentials are φ1f and φ2f respectively (f for ”final”). This condition...

Homework Statement A series RLC circuit is connected across a 6.70 kHz source. The 1.50 H inductor and the 1.35×103 kohm resistor are fixed whereas the capacitor is variable. At what capacitance will the current in the resistor be a maximum? Homework Equations No idea.. The Attempt at a...

Homework Statement Capacitors are connected as shown in this diagram: http://o3xn.files.wordpress.com/2012/04/c4.png C1 = 2 μF, C2 = 1 μF. What is the total capacitance of the system in between the terminals A and B? Homework Equations For capacitors C1 and C2 connected in...

Homework Statement Given two concentric spherical metal shells, with radii a and b (a < b), and surface charge densities Sa and Sb. Find the capacitance if Sa = - Sb. Homework Equations C = Q/V The Attempt at a Solution I would know how to solve this if the absolute values of the...

This is for an electromagnetic theory class. Homework Statement Prompt can be seen here Homework Equations J = I/A, J = σE, V = Ed, C = εA/d The Attempt at a Solution I'm having trouble mostly with parts i and ii, as the rest are fairly simple to acquire after figuring out those two...

Consider a thin parallel plate capacitor of an area of of 2.0x10^-4 metres squared, with a thickness of 1.2x10^-4 metres. The top and bottom thirds of the capacitor are filled with a dielectric material with a relative dielectric permittivity εr1=4, and the central third, with another material...

Homework Statement A 50 KW load operates from a 60 Hz 10KV rms line with a power factor of 60% lagging. Determine the capacitance that must be placed in parallel with the load to achieve a 90% lagging power factor.The Attempt at a Solution for 60% p.f:- θ1 = Cos-1(0.6) = 53.13 degrees Q1 =...

Hi everyone, I am trying to figure out how to correctly calculate the self capacitance of a multi layer coil. I have been trying to find an online calculator or software which can do this but I don't really know where to look. Just hoping someone here can give me some insight. Any help...

Homework Statement Find the potential difference, capacitance of the Geiger Counter and the charge on the anode. So, we have a Geiger Counter with low-pressurized neon inside. What we want is to have an alpha particle or electron to travel into the Geiger Counter with enough energy to collide...

What exactly is the reasoning behind deciding to use parallel vs series? What is the value behind capacitance, really, as opposed to a general electric circuit? Thanks.

Homework Statement I'm having trouble distinguishing exactly which combinations are in parallel and which are in series. The fact that both ends of the circuit are open is throwing me off. Can someone walk me through this?

If a capacitor's dielectric partially breaks down, as in some of the material has ionized and acted as a conductor, will there still be a capacitance to the component? Say its a high frequency AC signal on a capacitor with a small part of its dielectric material in a breakdown state. My...

can somebody give formula to calculate value of capacitance at co planar comb electrode as at the attachment..

So I left a thread of posts about this new coax I had made, trying to understand its electrical characteristics such as velocity factor and so on... Then I had an occasion to exchange emails with the MFG asking what the capacitance was per foot. The answer was something like 30pF per foot...

i have tried a lot but menacingly failed to understand how the parasitic capacitance exists in a pnp or npn transistor or at any diode??

Does the universe has a capacitance?

What is "kinetic capacitance" in superconductors or in solid state in general? Hi, I would appreciate it if anyone could explain to me what "kinetic capacitance" is, particularly in the context of superconductors or solids. I understand "kinetic inductance" which comes from the kinetic...

Homework Statement A capacitor is constructed from two square metal plates. A dielectric \kappa = 4.61 fills the upper half of the capacitor and a dielectric \kappa = 6.9 fills the lower half of the capacitor. Neglect edge effects. Calculate the capacitance C of the device. Answer in...

I've been playing around with projected capacitive touchscreens - specifically, the iPhone's. I've attached a white paper that outlines the details, but the basic idea is as follows: An iPhone's touchscreen has a dielectric layer sandwiched between a layer of conductors arranged in rows and a...

Homework Statement A parallel plate capacitor of area 2 cm^2 is filled with three dielectrics with constants k1=3.5, k2=1.7 and k3=8.5. The dielectrics are placed as shown in the figure, each occupying half the total area, while the volume of the first double of the other two. If the...

Hi, I am looking for a formula that calculates self inductance and capacitance of rectangular spiral coil, i came across many formulas for helical coil and circular spiral coil but couldn't find one for rectangular coil, any help is highly appreciated. Thanks

Homework Statement A parallel-plate capacitor has a plate area of 0.2 m2 and a plate separation of 0.1 mm. To obtain an electric field of 2.0 × 10^6 V/m between the plates, the magnitude of the charge on each plate should be Homework Equations Q=epsilon(E)(A) The Attempt at a...

Homework Statement Hi, I would really appreciate clarification on the definition of capacitance in this context: Suppose I have 3 concentric metal spherical shells and they have charges Q1,Q2,Q3 and potentials 0,V,0 and radii a,b,c respectively, what is the capacitance of the configuration...

Homework Statement An electronic engineer is designing a circuit in which a capacitor of capacitance of 4700 microFarads is to connected across a potential difference of 9.0V. He has four 4700 microFarads, 6V capacitors available. Draw a diagram to show how the four capacitors could be used...

Question for fun. A car's battery is not a capacitor, but it seems to "accumulates" charge the same way. So, if you take a typical fully charged car's battery, what would be the equivalent capacitance of a 12V capacitor that would have the same charge? For an extra kick - try to...

I do not know whether this is the correct section to post this. This is in my graduate level Electromagnetism class but the problem is sort of a "throw back" to the freshman level course. So I very much apologize if this is not the correct place! This problem shows a parallel plate capacitor...

Homework Statement If the separation between the plates of a parallel plate capacitor is doubled and the potential difference is held constant by a battery, the magnitude of the charge on the plates will: *a. double b. quadruple c. be cut in half d. not change Homework...

http://capa.physics.mcmaster.ca/figures/sb/Graph26/sb-pic2654.png This is more of a concept understanding if anything but I'm interested to know why the charge on capacitors A and B are the same and similarly, the charge on capacitor C and D are equivalent.

I have a question about electricity and magnetism. My teacher went through these chapters in 3 days, and I am completely confused. Can some body please explain what exactly is flux, capacitance, difference potential, and voltage? And can you also explain to my what the number stands for when...

Homework Statement C1 = 1μC ; C2 = 2μC ; C3 = 3μC ; C4 = 4μC V = 12.0V If both switches are closed, what is the charge on C1? Homework Equations q = CV In parallel - V is constant across capacitors Cxy = Cx + Cy In series - q is constant across capacitors Cxy-1 = Cx-1 + Cy-1The Attempt...

Hi All, I am at present working on coil design for RFID tag, i want to know how you add capacitance in spiral coil i.e. how you join two ends in spiral structure with capacitance in between, i have already calculated capacitance value needed to resonant at particular frequency. Any help is...

I want a capacitor bank capable of transferring a 350 kJ, 500 ms pulse. Or, rather, a bank capable of supplying 70 A @ 10 kV for 0.5 s. I have located a 2000 μf 10kV capacitor which looks like it might do the job. Unfortunately they are very expensive ($1500 USD) and I can only afford 2 or maybe...

The TMC channel is showing "Close Encounters of the Third Kind" which brings back the memory of RCAs Capacitance Electronic Disc. Anyone remember these? http://upload.wikimedia.org/wikipedia/en/thumb/e/ed/Ced_cart2.jpg/670px-Ced_cart2.jpg The first "video disk" I ever purchased/watched was:

Okay, so I know C=Q/ΔV And ΔV is the sum of the electric fields multiplied by the distance between the charges, so if the first charge has a charge of Q and the other has -Q with R distance between, the electric potential/voltage is: ΔV = [(kQ/r^2) + (kQ/r^2)]R so ΔV = 2kQ/R. And C = Q/ΔV...

Hi. I am working on a project for the design of a capacitive sensor. In order to do that, I am required to compute capacitance using a simulation software like COMSOL. As I want to compare my simulation results with the theoretical results, I would like to know the formula to be used for the...

Hi. I'm trying to understand a couple of things. When you put a piece of metal on, say the cathode of a battery, I suppose there is a charge transfer from the battery to the metal because the electrons on the cathode have a high potential energy? And so if I connect a piece of metal to both...

Capacitance between two plates is defined as the charge accumulated per unit potential difference between those plates. But in the case of transmission lines how can we define it? The potential difference any two conductors in a group of several conductors can be derived in terms of the charges...

Homework Statement A 10.0 uF capacitor is charged by a 10-V battery through a resistance R. The capacitor reaches a potential difference of 4.00-V in a time interval of 3.00 s after charging begins. Find R. Homework Equations C = Q/ΔV q = εC(1-e(-t/RC) The Attempt at a Solution...

Hey all I'd like to help me.. thnx in advance here z tha Q's : 1) Two plane parallel conducting plates each have area S and are separated by a distance b. One carries a charge +Q ; the other carries a charge -Q. Neglect edge effects a) What is the charge per unit area on each plate ? where...

What is the highest capacitance ever made/achieved? I am asking this because, when I am solving some time domain circuits, the values are given like 3 F etc. And I know that is absurd, and I really hate it because, if I didn't take electronics at home, I wouldn't have the feeling for...

Hi everyone. My problem is for an assignment in a network analysis course. I attached the homework page as a pdf. Homework Statement My problem involves an R-L circuit with a switch. There is a 100 V source, and switch that is initially closed, followed by a .25 H inductor and a 200 Ohm...

Only just started ac currents today and this was on my first quiz, I got 8/10 for it but got this question wrong. Homework Statement A 100 ohm resistor is connected in series with a capacitor and a power supply, and the supply voltage is brought up to 200 mV. The graph shows- for three...

Equivalent capacitance... A hard one!? Homework Statement Calculate Equivalent capacitance between A and B: [PLAIN]http://scsupport.org/moodle/file.php/13/Chapter26/imgch26q14.gif EDIT: If you can't see the picture, see 3rd post for file attachment, sorry!Homework Equations C1 = 3.55 µF C2 =...

Homework Statement You are part of an engineering research team that is designing a pulsed nitrogen laser. To create the high energy densities needed to operate such a laser, the electrical discharge from a high-voltage capacitor is used. Typically, the energy requirement per pulse (i.e., per...

HI all, A parallel tank circuit at resonance has a theoretical infinite impedance. However due to the resistance of L and C some power is dissipated so a small current will flow from the source. If a parallel tank circuit is oscillated at it's resonant frequency and a capacitor (C2) is...

Homework Statement 1. A parallel plate capacitor, with plates of area A, and spacing d, is filled with a non-uniform dielectric, with a permitivity that varies as ε = ε0 + ax where a is a constant, and x is the distance from one plate Homework Equations C = Q/V I'm...

Homework Statement Two capacitors C1 and C2 and a resistor R are all connected in series. At t=0, a charge Q1 resides on C1 and a charge Q2 on C2 (Q1 > Q2; C1 < C2), and the positive plate on C2 is connected to the negative plate on C1. a) In a first experiment, the positive plate on C2 is...

Homework Statement Homework Equations \int\vec{E}\cdot\vec{dA}=\frac{Q_{enc}}{\epsilon_{0}} \int\vec{E}\cdot\vec{dA}=\frac{Q_{enc}}{k\epsilon_{0}} V=\int\vec{E}\cdot\vec{dS} C=\frac{q}{V} C_{eq}=C_{1}+C_{2}+... \frac{1}{C_{eq}}=\frac{1}{C_{1}}+\frac{1}{C_{2}}+... The Attempt at...