Capacitance Definition and 874 Threads

Homework Statement I have the circuit above. When I have the switch at A, the capacitor C1 is charging at 100μF is at 10V. I then discharge the capacitor by connecting the switch to B. I was asked to calculate the time constant. I thought the capacitors were in parallel but according to...

Hello, i am reading one book over the "tenichians radio receiver handbook", but there was a stray capacitance can somebody help me, how to calculate stray capacitance? of what arethe standard value of stray capacitance thanks. YES do you see the circuits the stray capacitance is 7pf and 320pf...

So, I was studying force between the plates of a capacitor when a dielectric is inserted. Here is my question https://ibb.co/cenvXk Shouldn't it be like this picture below https://ibb.co/kOUsCk So, why is my teacher saying that the electric field inside the dielectric cancelling. So, what...

Homework Statement Homework Equations I want to know whether my process is correct? THANKS! The Attempt at a Solution [/B] 1. By using Gauss's law: E\cdot 2\pi rz = \frac{\lambda z}{\epsilon_{0}}\Rightarrow E=\frac{\lambda}{2\pi\epsilon_{0} r} In my coordinate system...

The side by side coils are round or oval, and wired together in series. Let's say the side by side coils are wound opposite (one clockwise and one counterclockwise) to match the direction of travel of the twisted coil's loops. Each of the side by side coils has the same number of turns as the...

Hi PF, I am in need of a capacitance in the zF (zeptofarad = E-21) range. Of course, they aren't sold this small, so I was wondering if maybe someone with more physics knowledge could help me create my own zF capacitor. Thanks in advance!

Homework Statement Consider a system of N isolated conductors,with arbitrary shape and position. We specify the charge Qi on the ith conductor for each i. The capacitance Cij is: Qi= ΣCijVj, sum over j. To prove: Cij = Cji Hint: Consider how much energy is needed to start with the system...

Homework Statement : [/B]Two conducting spheres of radii R1 and R2 are kept widely separated from each other. what are their individual capacitances? If the spheres are connected by a metal wire, what will be the capacitance of the combiation?Homework Equations Capacitance of a sphere of radius...

Homework Statement Two 3.0-cm-diameter aluminum electrodes are spaced 0.50 mm apart. The electrodes are connected to a 200 V battery. Find the capacitance of one of the spheres. Homework Equations [/B] C=QV C=ε0A/d The Attempt at a Solution [/B] I'm really not sure how to approach this...

Homework Statement I have an elementary doubt with the calculation of the capacitance of a capacitor of parallel plates that has a dielectric in the middle. https://ibb.co/b0W4BQ Homework Equations ∫D⋅ds=Q D=E+γP C=Q/V The Attempt at a Solution Suppose the top plate has a positive charge...

Hello all, I'm trying to measure the effect of adding charges in the silicon dioxide separating two interconnects in VLSI circuits and how it will effect the coupling capacitance between these two wires. How can I measure this effect ? The VLSI circuit I'm working on has frequency of 500...

Homework Statement Hi guys, I've been trying to solve these two questions for the last hour and can't seem to find the solution, any help would be very much appreciated. :smile: 1. An RC circuit is given a step voltage (charging) of V at t = 0 seconds. What is the value of voltage at t = 2RC...

Homework Statement Here is what I have so far. Am I going the right direction? If so, how do I go about finding the total current? Homework Equations See photo above. The Attempt at a Solution See above.[/B]

Homework Statement Homework Equations V=Ed Q = CV W = 1/2 QV The Attempt at a Solution Hi. My instructor gave me this problem as a homework. Actually he didnt teach us this subject. So what should i know to solve this question or from where can i study to this subject? Of course it would be...

Hi, I want to be able to vary the amount of capacitance in a circuit, ideally I'd like to be able to turn a knob to tap a bank of capacitors, something like the attached picture.Is there some sort of switching or device available that anyone can think of which does this? Cheers

How to find capacitance of parallel plate capacitor separated by conducting material with two different dielectric between Two parallel plate of Cu(5*6*0.1)mm and distance between them is (d=2mm) a thin Cu-plate of thickness 0.1 mm separates Mica layer & Quartz layer. how to find capacitance?

Homework Statement The plates of a parallel-plate capacitor are maintained with constant voltage by a battery as they are pulled apart. During this process, the amount of charge must... (decrease , increase , remains the same) Homework Equations C=Q/V C=E0(Area/Distance) The Attempt at a...

Homework Statement From the textbook: Homework Equations / 3. The Attempt at a Solution My attempt at the solution: looking to fix my issues and help correcting my work.[/B]

Homework Statement In attachments Homework Equations The Attempt at a Solution This is my charge distrubition.From there I draw electric field lines.And then from potential difference I wrote ##E=\frac {V} {d}## and then...

How does the load capacitance affect the Crystal. For example, IC manufacturers recommend a Crystal and also load capacitance, like 25MHZ, 16pF. What happens if I choose a xtal with load cap of 10pF 25MHz? I am talking about changing the load caps recommended by IC manufacturer, not the ones in...

Can someone help me on how can I get the value of capacitor on voltage multiplier and how can i double the voltage through a 20 ohm load resistor?

I need help trying to set up this problem. I want to find the capacitance between a point charge and a finite plate (or disk) as the point moves from above the center of the plate to some distance off the plate. I have been able to simulate this problem using FEM, however, there should be a...

Homework Statement A capacitor is made of two parallel plates of area A, separation d. It is being charged by an AC source. Show that the displacement current inside the capacitor is the same as the conduction current. Homework Equations Idisp = ε(dΦE/dt) Q = CV C = Aε/d Xc = 1/(2πƒC) Q(t)...

Homework Statement Find the equivalent capacitance between points A & B Homework Equations Ceq1 = C + C 1/Ceq2 = 1/2C + 1/2C + ... The Attempt at a Solution [/B] It is my understanding that each capacitor top and bottom are connected in parallel, so their equivalent is 2C. Now, they...

Homework Statement Below are a few equations listed in my text for use in calculating capacitance in dielectrics. I'm wondering which of these are applicable in specific scenarios Homework Equations 1. k = C/C0 - with C0 indicating capacitance w/o dielectric 2. v = v0/k 3. E = E0/k 4. σi = σ(1...

Homework Statement Homework Equations C=Δq/VThe Attempt at a Solution So part a: The capacitance of 3 should be the difference in charge of b and a divided by the voltage of the circuit? C3=(14μC-6μC)/12V =6.67*10-7 F This was wrong...

Hi. Inductance and capacitance have many analogies, both conceptually and formally. A capacitor connected to a voltage source carries the charge ##Q=C\cdot V##. The analogous equation for inductance is ##n\cdot \Phi=L\cdot I##. Charge is physical, it's proportional to the number of excess...

Homework Statement Write an expression for the total charge on one of the plates of the capacitor. Is this total charge greater than, less than, or equal to the total charge on one of the original plates? http://imgur.com/enJ1wMy (It won't let me paste the image so this is the best I could...

Homework Statement A spherical capacitor is formed from two concentric, spherical, conducting shells separated by vacuum. The inner sphere has radius r the capacitance is C. What is the outer radius R? Already solved the problem, but I'm more wondering on how to derive the equation that I...

Homework Statement The circuit has been completed for several minutes. Suppose that ε = 55 V . Calculate the magnitude of charge on the 100 μF capacitor plate. Homework Equations Q = C * V The Attempt at a Solution Since the capacitors have been fully charged, current has stopped flowing at...

Homework Statement In the circuit shown in the figure below, the hase difference between the current and the voltage is 30 degrees, show how could you verify the capacitance of the conductor so that the phase difference could be 15 degrees. Homework Equations tan θ=-Xc/R (the phase difference...

This is my first post and am curious if anybody here has any experience or advice on how to discharge a capacitor bank with 6 1F capacitors connected in parallel. I built a electric hybrid (basically electric transmission) vehicle that uses a 31hp gas engine to power a 23kW (peak) DC generator...

Assume that we have two charged spheres with unequal radii and which do not overlap. How cold we express their capacitance?

Homework Statement Two large parallel metal plates are oriented horizontally and separated by a distance 3d. A grounded conducting wire joins them, and initially each plate carries no charge. Now a third identical plate carrying charge Q is inserted between the two plates, parallel to them and...

Suppose that the radius of Earth is 6400 km. Then what will be the capacitance of the Earth in micro farade unit?

Hello, suppose I have four conductors (1,2,3,4) and I know their mutual capacitances cij where i,j∈{1,2,3,4}. Note that the quantities cij are essentially the elements of the capacitance matrix of this system. Now, if I apply a voltage to two conductors and leave the other two grounded (e.g...

Hello, 1. Homework Statement Assuming that the dielectric is inserted at a constant rate, find the current I as the slab is inserted. Express your answer in terms of any or all of the given variables V, K, r, d, Δt, and ε0, the permittivity of free space.Homework Equations [/B] C = ε0 * A /...

1. The problem stsatemesnt, all variables and given/known data A cylinder conductor of length ##l##, inner radius ##a## and outer radius ##b## is half-filled with a liquid dielectric as shown in the picture. The cylinder is attached to a battery of constant voltage ##U## and then separated from...

Homework Statement For a given system, a conducting cylinder with radius ##r=a## with a linear charge density ##Q'## and a conducting surface at a distance ##z=h## from the cylinder, calculate the linear capacitance of the cylinder.Take that ##h>>a## ##C'=\frac{Q'}{U}## Homework Equations 3...

I have spent hours on the web and in libraries to obtain a general and careful approach to the notion of capacitance, without success. Please, read carefully the question: I already know the usual blabla about capacitance. Also, I appologize in advance for the length of this question. I...

Millikan Oil drop experiment. For my current lab, we are recreating the milian oil drop experiment to measure the charge of an electron. However, we are using 1-micron diameter latex spheres in place of oil drops. Problem: I am having difficulty deriving an equation for the speed of the drop...

Homework Statement Hello everyone, I am trying to figure out how to approach part c, parts i and ii Homework Equations OK. I know that we have the current equation in milliamps as shown above The Attempt at a Solution My problem is giving one possible explanation for the finding and...

This is a simpler issue but I need some help nonetheless. I have been carrying out an investigation on how the dielectric size of a capacitor affects its time constant. In theory the larger the dielectric the smaller the capacitance and therefore the smaller the time constant. However although I...

Why is there a shunt capacitance in a transmission line, but not in a normal circuit (non-transmission line).?

This may well be a textbook question, or even a duplicate in this forum, but I have no idea of how to compute the capacitance between two conductors in the general case: all the computations I saw in textbooks make heavy use of symmetries to compute the capacitance, e.g. capacitance between two...

Hi everyone. I have quite a basic doubt, and I thought you could help me. Consider the figure: The cylinders S1 is held at a constant potential, and the same applies for the ring identified by S0. All the surroundings are filled with an insulator material. I want to calculate che capacitance...

Homework Statement Calculate the equivalent capacity of the capacitor system between points ##x## and ##y## Homework Equations ##C=q/V## The Attempt at a Solution I'm asking about this problem because I know how to calculate ##V_x-V_y##, but I don't know how can I extract the equivalent...

Homework Statement Homework Equations C = q / voltage The Attempt at a Solution OK. [/B] By Kirchoff's Voltage Law, we have: EMF - ( q / Capacitance)x - (q/Capacitance)y = 0 Now. I know that having the dielectric increases the capacitance of X, so the voltage drop across it is smaller...

1. The problem statement, A capacitor is there in free space consisting of 2 circular plates of radius ##r## separated by a distance ##z## which is a function of time. ##z(t) = z_0 + z_1 cos (\omega t)##; ##z_0(<<r)## and ##z_1(<z_0)## are constants. The separation ##z(t)## is varied in such a...

So I read a page where someone said they had put 18 400v 3900uF capacitors in parallel and that this came out to 5600 joules... Now I'm sure I am doing something wrong but when I did it out I only got 28.08 joules... I used this website...