Capacitance Definition and 874 Threads

I understand how to calculate the capacitance of an isolated conductor, say a sphere, and I know that the associated formula involves the surface area of the conductor. Does all of this make the assumption that the surface in question is convex, or at least "non-concave"? More specifically, what...

Homework Statement A parallel-plate air capacitor is made by using two plates 18 cm square, spaced 3.5 mm apart. It is connected to a 3-V battery. What is the capacitance? Homework Equations C = εo(A/d) The Attempt at a Solution εo = 8.854e-12 A = .18 m d = .0035 m...

Homework Statement Calculate the equivalence capacitance of the network; where C1 = 8.55 μF, C2 = 4.00μF , C3 = 8.65 μF, C4 = 3.20 μF http://imageshack.us/content_round.php?page=done&l=img822/4296/loncapa.gifHomework Equations Capacitane in parallel: C = C1 + C2 + ... Cn...

Homework Statement http://loncapa2.fsu.edu/enc/66/45d3639022485d2ba995cf84c579b584bffe5ace9851f3da3fbac5f5a1c7d2ee9dfed8743cf75459ef336ad7a1bbe176f7a0cf1a35a519ce0cef3c31febf9858404cac5a2cd3ace3851dbef61ee03a25f7a5c41a87b32e0f.gif Calculate the equivalence capacitance of the circuit shown...

I am designing a small step up transformer and I'm trying to calculate leakage inductance and winding capacitance. The problem I'm having is when I search the web I find there is a ton of info on the subject. So I have no idea where to start. Can anyone explain to me how to calculate...

Hi, Does anybody know a nice formula for the capacitance of two metallic wire loops with equal radius R? (The center of the loops are above each other, their distance is d. The whole system is in vacuum) Thank you!

Homework Statement A capacitor with C = 4600 μ F is fully charged using a 12 V power supply. At time t = 0, you start discharging the capacitor via a 50 k Ω resistor. Calculate the initial charge Q max (in mC) and the initial energy E max (in mJ) stored in the capacitor. Then, calculate...

Homework Statement Determine the equivalent capacitance of the combination shown in Figure P26.75. Suggestion: Consider the symmetry involved. Homework Equations Parallel is: C1+C2+C3+... Series is: (C1^-1 + C2^-1 + C3^-1 + ...)^-1 q = CV The Attempt at a Solution I have no...

I've run the experiment. By varying the current and fix the mass of the electrode, I found out that the specific capacitance (Csp) is increased when applied current (I) is increased. By using this formula, Csp = 4I / [M*(dV/dt)], where I is the applied current, M is the mass of both...

Homework Statement Initial Conditions (a) Switch S2 kept open, switch S1 closed until C1, C2 and C3 are fully charged. What is the potential difference across each capacitor? Now Switch S2 is closed. What is the new potential difference across each capacitor? (b) Switches S1 and S2 are both...

I know that the there is some small capacitance between the windings of an axial inductor let's say, but how does one measure this? The inductor is a short on an LCR meter...

Homework Statement The Earth can be considered as a single-conductor capacitor. It can also be considered in combination with a charged layer of the atmosphere, the ionosphere, as a spherical capacitor with two plates, the surface of the Earth being the negative plate. The ionosphere is at a...

Homework Statement A potential electrostatic difference is stablished between points M and Q in the cubic circuit of identical capacitors shown in the image. What is the potential difference between points N and P? Homework Equations The Attempt at a Solution I tried opening up...

Homework Statement I'm trying to find the equivalent capacitance for a circuit, but I keep getting stuck. Homework Equations C(parallel)=C1+C2+...Cn C(series)={(1/C1)+(1/C2)+(1/C3)+...(1/Cn)}^-1 The Attempt at a Solution See the first penciled attachment.

Homework Statement The energy of the RLC circuit decreases by 1% during each oscillation when R=2 Ohms. If this resistance is removed, the resulting LC circuit oscillates at a frequency of 1 kHz. Find the inductance and the capacitance. Hint: be aware of the difference between regular and...

How can you measure a capacitance of an isolated object, like a conductive sphere or a coil? Can it be done using a typical RLC meter? I've tried touching only one end of the probe to the object in question, and that seems to give sporadic readings, but within the order of magnitude of the...

Hi, I am new here. I need to know the formula for the capacitance of a toroid of circular cross section. I found this: http://deepfriedneon.com/tesla_f_calctoroid.html But I need to show the proof for the formula. Can anyone help?

I need help with something.I have problem to understand how the capacitance of a capacitor can be increased if we move the plates of the capacitor more close. Here's my reasoning: The capacitor is just a extended terminal of a battery,so the battery voltage must equal the capacitor...

Homework Statement ions and electrons produced in the electric field between the hand and the plate (3.0 x 10^6 Vm^-1) are accelerated and may collide with other particles, causing further ionisation. Calculate the force on an electron in this field. Homework Equations E=V/d The Attempt at...

Looking at this datasheet: http://www.ti.com/lit/ds/symlink/lm386.pdf Most circuits near the bottom have a 250uF cap in line with the output. Would changing this cap affect the audio signal or would it just further smooth out the waveform?

Homework Statement An isolated charged parallel-plate capacitor with the plate separation d=2 mm and area of A=10 cm2 is initially empty. One slides a polystyrene dielectric slab with thickness equal to half the plate separation and with only half the area of the plates into the region between...

Homework Statement This is an EM waves class, but we are given the following problem, which seems deceptively simple. I'd like some feedback to see if this is done correctly. Homework Equations Consider a parallel plate capacitor connected with a resistor with resistance R, as shown in the...

Homework Statement Homework Equations 1/Ceq= 1/C1 + 1/C2 The Attempt at a Solution 1/C13eq= 1/3C1 + 1/5C3 = 8C/3 = 2.67C 1/C12eq= (3C x C)/(3C + C) = 0.75C Ceqtotal = 2.67C + 0.75C = 3.42C I think the series circuit is throwing me off?

1. Homework Statement Calculate capacitance of LC Circuit where: Inductor - 30H Capacitance voltage fully charged goes to zero in 20 seconds 2. Homework Equations Main Eq: V=V. *cost(ωt) where V is final Voltage, V. = Voltage initial, ω = resonant angular frequency ω = 1/√(LC)...

Homework Statement Calculate capacitance of LC Circuit where: Inductor - 30H Capacitance voltage fully charged goes to zero in 20 seconds Homework Equations Main Eq: V=V. *cost(ωt) where V is final Voltage, V. = Voltage initial, ω = resonant angular frequency ω = 1/√(LC) = 2∏f f. =...

Hello, I am designing a wireless energy transfer system and would like a formula to calculate the distributed capacitance in a circular coil of N turns. Any kind of assistance is really appreciated.

Homework Statement A capacitor is formed by 2 square metal plates of edge a and separated by distance d. Dielectrics of dielectrics constants K1 and K2 are filled in the gap as shown. 2. The attempt at a solution This was my initial approach: I integrated the parallel combination of...

Hi, I did an experiment, involving transformers. Where we did open circuit and short circuit tests then test with a resistor, capacitor and inductor. For the last question it asks Calculate the load capacitance and inductance from the voltage regulation readings. Voltage regulation...

Hi, So I am learning about parallel-plate capacitors. The way my book puts it is that it is basically two parallel plates of opposite polarities, separated by a distance d. In order to establish that distance, work must be done and the energy is stored as electric potential energy. From...

Homework Statement Find VL(t) and Vc(t) in the circuit below Where Vs = cos(200\pit) V Homework Equations \alpha = \frac{1}{2RC} ω0 = \frac{1}{\sqrt{LC}} \omega0 = \sqrt{\omega^{2}-\alpha^{2}} The Attempt at a Solution Well, I found the total capacitance C = 1.5 uF Then, I found \alpha...

Hello, I came across this topic while reading Principles of Electrodynamics which can be read from this link starting at page 54. Looking at page 56, my question is how could there be induced charge on a grounded conductor ? what happens then to the equation Q = C * V, where Q is charge...

ok i need to know the value of the capacitor which i need. i have a pulse voltage of 6mV which i want to stabilise to create a voltage which will power a small L.E.D. i currently have a bridge rectifier and i know i need a capacitor but what would the value of this capacitor be.

Problem: (a) What is the capacitance of the 2 conductors +20nC and -20nC? (b) If the voltage difference between the 2 conductors increase to 250 V, then what else changes? a). I calculated that ΔV = 100 V. So then I plugged into the formula C = Q/ΔV. I thought 20 nC = 2 x 10^-8 C, which...

the given is 3mF is parallel to 11mF and 9mF in series connection and it is also parallel to 12mf and 6mf series connection my answer to this is 1.17*10^-5 is this correct

The Problem: An empty capacitor is connected to a 12.0 V battery and charged up. The capacitor is then disconnected from the battery, and a slab of dielectric material (k=2.8) is inserted between the plates. Find the amount by which the potential difference changes, and state whether this change...

Homework Statement The charge on a 2-microfarad capacitor is given by q(t)=10^-6 * sin(10^5*t) C find the dexpression for the voltage and current? Homework Equations The Attempt at a Solution the answer is v(t)=0.5sin(10^5t) , i(t)=0.1cos(10^5t) i don't get how they found the answer

Hi, Hopefully this is going to be pretty basic stuff for someone. I have a mechanically variable capacitor and to prevent electrode shorting, I have deposited a small amount of oxide on the side walls. For my Matlab model I need the equation for capacitance which takes this oxide into...

Capacitance -- How handle multiple caps in series and parallel? I can't draw the circut for the cuestion so I attached it. I am having trouble finding the charge across capacitor 2. I don't understand what to do with the 3 capactiors right in that group and how to figure the change in voltage

Hi, Question: Consider two conducting spheres with radius R, which are tangential each other (i.e. they touch right at one point) If C = Q/V, where V is the potential at the surface, find the capacitance of this configuration...

Homework Statement The actual value of the capacitor Rahal will receive may be different from the value the catalogue states. The manufacturer guarantees that the maximum percentage difference below/above the catalogue value will be –10% / +50%. Rahal orders one of the 400 V 1000 µF...

Homework Statement Calculate the charge on C1 in Coulombs. Homework Equations umm q=CV The Attempt at a Solution http://answers.yahoo.com/question/index?qid=20120424171750AA1WxRv I have this same problem except my numbers are: C1= 6.00 μF, C2=3.10 μF, C3= 2.20 μF, C4= 1.30...

Homework Statement Calculate the equivalent capacitance of the circuit shown in the diagram above; where C1 = 5.30 microF, C2 = 8.45 microF, C3 = 5.65 microF, and C4 = 8.60 microF. Homework Equations parallel: Ceq = C1 + C2 + etc series 1/Ceq = 1/C1 + 1/C2 + etcThe Attempt at a Solution...

Homework Statement As shown in the figure, a very thin sheet of aluminium in placed in between the plates of the condenser. Then the capacity (a) Will increase (b) Will decrease (c) Remains unchanged (d) May increase or decreas Homework Equations Dielectric strength of a metal. The Attempt...

Homework Statement Homework Equations The Attempt at a Solution I don't have any idea on this. Firstly, how are the capacitors connected? are they in series or parallel? What happens to the charge on plates of first capacitor when the capacitors are connected in parallel? Any help is...

Homework Statement Find the capacitance of a capacitor that stores 320 MJ(MegaJoules) when the potential difference across its plates is 170V. Answer must be in nanofarads. So basically q: is 320MJ V: is 170V I need to find C the capacitance. Homework Equations To find the...

Lets say There is a capacitor with the are of Plates A and the distance between the plates say is 5m if a dielectric of similar dimensions except the width is 3m is filled between the Capacitor plates how to calculate the new Capacitance ??

A series RLC circuit connected to a 100-V 60-Hz source draws a current of 2.5 A. The measured power factor for the circuit is 0.7 leading, and the inductive reactive power is 300VAr. Calculate the resistance, inductance and capacitance of the circuit and show the corresponding impedance...

Homework Statement The Question is to find Effective capacitance in the circuit shown below (Sorry if the pic is not clear enough) Homework Equations This is in the Chapter Capacitors so the basic formula that would be used I guess is Q = CV The Attempt at a Solution First I...

Our professor gave us a lecture about sensors tonight, but I'm kind of confused about the principals of capacitive touch screen. As the attached figure shows, when finger touches the screen , capacitance is formed between finger and the ITO bars, but is it true for all the ITO bars? It's...

In Jackson's book he defines the capacitance of a conductor, "...the total charge on the conductor when it is maintained at unit potential, all other conductors being held at zero potential." I'm trying to get a more concrete definition in my head rather than the standard definition of...