Dielectrics Definition and 141 Threads

I'm reading my physics textbook right now and it states that when you add a dielectric between two capacitors you are: 1. Increasing the potential difference between the two plates. 2. Increasing capacitance by decreasing V (Q/V=C) Isn't this contradictory? I thought that V in the equation...

Homework Statement Find the capacitance of the parallel plate capacitor with 2 dielectrics below. Given that the parallel plate capacitor has area A = WL and the separation between plates is d. The Attempt at a Solution My method is to use integration. First solve for two small...

b]1. Homework Statement [/b] Electrostatic clamps are used for holding workpieces while they are being machined, for holding silicon wafers during electron beam microfabrication, etc. They comprise an insulated conducting plate maintained at a potential of several thousand volts and covered...

Hi. The chapter is electric potentials. In dielectrics, when solving for Q(bound), Q(free) is required. What is Q(free)? Is it Q with OR without the dielectric factored in? Or is C(knot) alone? Joben.

Say i have a capacitor and i supply it with a voltage V and after that it has charge density sigmainitial on each plate. Now i remove the voltage source and then introduce a dilectric with area A that it equal to the area of one of the plates in the capacitor to the capacitor. But this...

I could do with a table that's shows The meduim Reccomended Functions Pakages Polorised or not Capicitor values Tollerance ranges Anything near to that would be great Thanks

[b]1. A vertical parallel-plate capacitor is half filled with a dielectric for which the dielectric constant is 1.97 (Fig. P26.70a). When this capacitor is positioned horizontally, what percentage of it should be filled with the same dielectric (Fig. P26.70b) so that the two capacitors have...

Ok so I know that multiple dielectrics inserted into the space between two plates one on top of the other and not side by side should be treated as capacitors in series and the overall capacitance should be calculated this way but why? I can't find the theory behind this anywhere in my text.

I cannot figure out this problem...can someone help me? A 3500 air-gap capacitor is connected to a 32 battery. If a piece of mica fills the space between the plates, how much charge will flow from the battery? Express your answer using two significant figures.

I was getting ready for a test in my physics class and have a question that I cannot figure out. Why does adding a dielectric to a capacitor cause the amount of charge that can be stored to increase. I understand what a dielectric is and how a capacitor works but am just not sure why this...

Homework Statement Two capacitors are identical, except that one is empty and the other is filled with a dielectric (κ = 3.20). The empty capacitor is connected to a 11.0-V battery. What must be the potential difference across the plates of the capacitor filled with a dielectric such that it...

Homework Statement Fig. 1 and 2 show a dielectric slab being inserted between the plates of one of two identical capacitors, capacitor 2. Select the correct answer to each of the statements below (enter I for `increases', D for `decreases', or S for `stays the same')...

Hi. I have a problem in trying to find the field \vec E in the following situation: I have an infinite charged plane, with charge density \sigma , and two dielectrics, like in picture: http://img53.imageshack.us/img53/2301/testrb0.jpg Now, if i think of \vec D being orthogonal to the...

Homework Statement Two long coaxial cylindrical metal tubes (inner radius a, outer radius b) stand vertically in a tank of (dielectric) oil (suceptibility X-e, mass density rho). the inner one is maintained at potential V, the outer one is grounded. to what height (h) does the oil rise...

Hi guys, I'm absolutely, completely and utterly stumped with this one question I've been given.. Here is the exact question: Given that you possesses the following materials: (i) two sheets of copper of uniform thickness; (ii) one sheet of mica of uniform thickness 0.10 mm and dielectric...

hi everyone, I've got a question. say i have two electrode plates placed pretty close together, with two pieces of a ceramic high dielectric constant material.. x7r class ceramics for instance, in between the two plates, with a gap in the middle of these two ceramic inserts, filled with...

[SOLVED] Capacitors with partial dielectrics Homework Statement Consider two parallel-plate capacitors identical in shape, one aligned so that the plates are horizontal, and the other with the plates vertical horizontal: vertical: The horizontal capacitor is filled halfway...

suppose I have a charge q at (x=-d) and a charge q at (x=+d). the force between them is q^2/(4*pi*(eps_0)*4*d^2). now, I insert a dielectric (K) between (-d/2<x<d/2), and try to calculate the force now... it seems like it would be the same but it sounds strange... If I use the D field...

Homework Statement Say I have a boundary between two dielectrics then it's easy to show using a gaussian pillarbox that: D(1)-D(2)=free surface charge density=s where D(1) is the component of the first medium normal to the surface. But suppose that there's nothing else apart from two...

For a capacitor not connected to a battery, why does the voltage decrease with the insertion of a dielectric. Would it be because the net electric field between the conductors is decreased?

[SOLVED] Capacitor with 2 dielectrics Homework Statement A parallel plate capacitor of plate area A and spacing d is filled with two parallel slabs of dielectric of equal thickness with dielectric constants k1 and k2, respectively. What is the capacitance? Homework Equations You tell me. The...

A capacitor has a capacitance of 50 pF, which increases to 150 pF when a dielectric material is between its plates. What is the dielectric constant of the material? C = 150 pF and Co = 50 pF Therefore Dielectric constant K = C/Co = 150 pF/ 50 pF = 3

Hello everyone, First and foremost I would like to see if everyone's having a good day? (assuming you respond yes) Awsome! Secondly I was hoping someone would be able to help me understand how dielectrics work. I don't need to know everything about dielectrics. I only need to know how...

the answer i keep getting is wrong ... help? Homework Statement Two parallel plates of area 110 cm2 are given charges of equal magnitudes 9.6 × 10-7 C but opposite signs. The electric field within the dielectric material filling the space between the plates is 4.2 × 106 V/m. (a)...

Homework Statement An air-insulated parallel-plate capacitor of capacitance C_0 is charged to voltage V_0 and then disconnected from the charging battery. A slab of material with dielectric constant \kappa, whose thickness is essentially equal to the capacitor spacing, is then inserted...

A little bit of confusion: Is it not correct to write ▼. E=ρ/ε0 inside a dielectric body. As far as I know we should write ε instead of ε0.[where ε=εr*ε0] Then why do we write ▼. E=ρ/ε0 inside a conductor?

\alpha =\frac {\omega \epsilon \prime \prime} {2} \sqrt {\mu \epsilon \prime} My question is what exactly does the \epsilon \prime \prime term signify?? I see sections of my notes that say \epsilon \prime \prime << \epsilon , but what is it? I mean when I am trying to find the attenuation...

Let's see if I understand this correctly... In an isotropic material of conductivity \sigma \neq 0 (and charge density \rho=0, the 4th Maxwell equation has a non-null current term \vec{J}=\sigma \vec{E} so the resulting wave equations for \vec{E} and \vec{H} take the form \nabla...

This is a conceptial problem. A slab of dielectric, with a dielectric constant K between an isolated parallel-plate capacitor, is removed. The two plates of the capacitor have charges Q and -Q, which do not change when the slab is removed. Is the energy stored in the capacitor more, less, or...

Hi all, I'm looking for information/theories/data/phenomenology about micro discharges in dielectrics (and surfaces). I'll explain the problem: we have some conductors under a potential of ~2500V which are (of course) in contact with solid dielectrics (types of plastic, ceramics...), and...

Two capacitors are identical, except that one is empty and the other is filled with a dielectric ( k= 5.00). The empty capacitor is connected to a 6.0 V battery. What must be the potential difference across the plates of the capacitor filled with a dielectric such that it stores the same amount...

1. can someone please explain the idea of a dielectric to me (or at least give me a link that explains it in laymans terms) - all i understand is that its placed between two capacitors and it increases their capacitance (by the factor of K). what does it do to the voltage? and the charge...

Here's the problem: http://img41.imageshack.us/my.php?image=efield3od.png Can anyone give me a push in the right direction? I'm really stuck on two things - how does the cavity affect the problem (the hint doesn't really help me), and what does the geometry of the problem (since I'm giving...

I have a question that is confusing me perhaps one of you can help me. If I hook up a constant potential difference to a capacitor and place a dielectric inside of it, will the electric field decrease even if the plate separation remains constant? I think that the capacitance will increase as...

I have a nasty problem here which I have been working at for a while but keep getting rubbish answers. I have tried using: E = surface charge density/(dielectric constant * Epsilon0 (8.85*10^-12) but I get a dielectric material which has a lower dielectric constant than air. I really...

OK I just want to start from the beginning and try to get the first part of this problem so I can get what is going on in my head and understand it. Here's the problem: A point charge q is imbedded in a solid material of dielectric constant K. A) Use Gauss's law as stated in equation...

This problem is also giving me a lots and lots of trouble, and I don't even know where to begin. A point charge q is imbedded in a solid material of dielectric constant K. A) Use Gauss's law as stated in equation \oint{K \vec{E} \cdot \vec{A}} \;=\; \frac{Q_{free}}{\epsilon_{0}} to find...

I have a lab to do tomorrow with this topic. Just wondering if anyone can tell me a brief summary of what this is about and what I should be looking to accomplish/learn

Hey everyone, this is my first question on here, but I've seen you all be very helpful to others to I was hoping someone could clarify something for me. 1. How does Gauss law modify in dielectric materials?

I need some help with these problems: 1) A parallel-plate vacuum capacitor has 7.36 J of energy stored in it. The separation between the plates is 3.64 mm. If the separation is decreased to 1.40 mm, what is the energy stored if the following events occur? a) the capacitor is disconnected from...

I am supposed to design an energy storage system for a car, so I want to calculate how much energy can be stored in a capacitor whose geometry matches the car. As a baseline, we have an area 150 cm wide by 2500 cm long by 30 cm tall. The capacitor is a sandwich geometry , one layer of...