Capacitor Definition and 1000 Threads

First, I think that I need to calculate the capacitance. It is ## C=\epsilon_0*\frac{l*w}{d}-x*\frac{w*\epsilon_0}{d}+\epsilon*\frac{x*w}{d} ##. After that I should calculate the potential energy. It is ##U=\frac{1}{2}*C*V^2 ##. After that I should take its gradient to get the force. So ##\vec F...

so the result I got is the energy lost by the field right??

This is not my homework. I took it upon myself to answer a textbook question for mental stimulation. I wanted to know if someone can verify if these were the correct values that needed to be solved for, process, and final answer, and if not, what needed to be considered. For the initial...

Specifically for part (i) and (ii), I get the rough idea that when the voltage of the AC source is decreasing, the capacitor can discharge to "cushion" the drop in voltage. However, I have some questions about when this occurs. 1. There is an assumption that the capacitor will be charged to...

I have 2 methods, which give 2 different solutions: Let sigma = charge per unit area Let plate 1 be the left plate, plate 2 = right plate. Method 1: Because they are insulating, consider the electric field at 3 regions; region 1 to the left of plate 1, region 2 between the plates, and region 3...

Hi, I am trying to find the insulation resistance of a specific capacitor. I've posted on balancing resistors before and got some pretty helpful information. The previous datasheet gave the information in a different manner though. I'm hoping someone can help me decipher the insulation...

The problem is shown below: (I am only asking about part b) ^Above is the problem. Below is the solution to part b. They have claimed that we can set potential at C = D = u(t), and A=B=0. Why is this claim true? What I realize: By applying Kirchoff's across ACDB, Voltage across C1 = Voltage...

Question 1: a. I am aware that the general equation for capacitance is C=Q/V thus Q=CV. 22 μF = 0.000022 or 2.2*10^-5 F Would the charge stored by equal to Q=2.2*10^-5*12 Thus, Q=2.64*10^-4 C b. The energy stored by a capacitor is given by E=1/2QV=1/2CV^2=1/2Q^2/C I think with the information...

Hi, I found the following question in a physics book, and so dusted off my 30yr old knowledge on capacitors and tried to answer it. The question is as follows :- "Suppose two nearby conductors carry the same negative charge. Can there be a potential difference between them? If so, can the...

I use the following equations to understand this question/answer. First, C = k(ε*Area)/distance = Q/V = Q/ (E*distance) As a slab of glass is added, k increases and thus E decreases. F=QE, as E decreases, force decreases as well. How does this relate to the 'force attracts the glass into the...

If none of the above is correct, what is a good definition of the symbol t (time)?

BaTiO3 thickness = 7mm = 0.007m dielectric constant = K = 1260 dielectric breakdown = E = 97MV/m (97kv/mm) (Structural, Dielectric and Ferroelectric Properties of Tungsten Substituted Barium Titanate Ceramics, 2009) LDPE thickness = d = 0.007m dielectric constant = K = 2.3 dielectric...

2 separate big conductors initially charged Q1 and Q2. Then connect them in a circuit with a battery of emf V. The charges Q1 and Q2 will go to the 4 surfaces (marked red). All the 4 surfaces have an area A. Suppose the 2 conductors form an ideal parallel plate capacitor and the wires in the...

I already how to properly set it up and execute the equation with natural log etc. 2/3q0 = q0e^(t/RC) 2/3 = e^(-t/tau) ln(2/3) = -t/tau t = -ln(2/3)tauThe problem should be trivial; however, -ln(2/3)tau is apparently incorrect. So is ln(3/2). Is there something I am missing?

I am looking at capacitor selection for a switched capacitor converter and I'm not sure which voltage rating to look for. I've was going to consider the DC rating since they're holding off a DC voltage, but they are subject to PWM excitation since they're switching between nodes at different...

The diagram would look like this. a. The total energy is conserved, ##KE_A + PE_A = KE_B + PE_B ## ##KE_A=0; PE_A =1000## ## 1000 = \frac{m v^2} {2} ## ##2000 = {9.1}*10^{-31}*v^2## ##v^2 = \frac{2000 * 10^{31}} {9.1}; v = 46.8 * 10^{15} ## ##v = at; = \frac {qVt} {md} ; t = \frac{vmd} {qV}...

Could somebody check my solution?

I've been working on designing an experiment over the past few weeks as part of a school project, under the supervision of a teacher. I have designed a small low-power coil-gun. I have a coil of roughly 60m 24 AWG copper wire wrapped around a length of 2.5cm of clear PVC pipe. I tested the...

$$R_{eff} = R_1 + \frac{1}{\frac{1}{R_2}+\frac{1}{R_3}} = 1.4 + 0.6 = 2$$ PD of R3 = 4 / 2 * 0.6 = 1.2 Net PD of the capacitor = 2- 1.2 = 0.8V $$ E = \frac {1}{2} CV^2$$ E = 0.8 ^2 * ( 3*10^-6) / 2 E = 9.6 * 10^-7 Correct answer is: 4.27 * 10^-7 was thinking if i should find the Effective...

A friend has a single phase, cap start induction motor with the following characteristics: V 240/250 A 2.6 Hp 1/3 Rpm 1435 @ 50Hz As for as I know it’s not fitted to a machine, but given the low hp rating I’d guess it’s for a drill press. So it would need only moderate to low starting torque...

Not sure how to set this question up or how to get to the second half

The capacitance must be found, that is: ##C=\frac {Q}{V_a-V_b}##. Let ##\vec{E_d}## and ##\vec{E_v}## be the electric fields due to the zone with dielectric and the zone without dielectric respectively. In the case of a spherical capacitor with a vacuum between its plates, it is easy to...

I'm having a few troubles understanding a few things about this circuit... Firstly, what does "In light of this, the potential between the resistors is ##16V##" exactly mean? If current isn't flowing, how could there be a potential between resistors? Secondly, how does current flow with the...

Using: $$i(t)=\frac{U}{R}.e^{-\frac{t}{RC}} As the power is constant, then the current will be constant, so: t/RC is constant I don't know how to proceed anymore. I think you should use some derivative, but I'm still very new to that part, so how can I proceed?

Does anyone have a reference or solution for a parallel plate capacitor in the Rindler metric? I'm particularly interested in the case where the capacitor plates are in the xz or yz planes, z being the direction of the acceleration. The motivation is to get an idea how a transmission line...

1)$$\frac{Q}{\Delta V}=\frac{\kappa\epsilon_0A}{\ell}\Leftrightarrow\Delta V=\frac{Q\ell}{\kappa\epsilon_0A}$$$$I=\frac{A\Delta V}{\ell\rho}=\frac{Q}{\kappa\epsilon_0\rho}$$ 2) The charge is decreasing by ##\Delta Q##, so ##Q(t)=Q-\Delta Q##.$$I=\frac{\Delta Q}{\Delta t}\Leftrightarrow\Delta...

a)$$C=\frac{\kappa\epsilon_0\ell x}{d}+\frac{\epsilon_0\ell(\ell-x)}{d}=\frac{\epsilon _0ℓ\left(\kappa x+ℓ-x\right)}{d}$$ b)$$U=\frac{1}{2C}Q^2=\frac{dQ^2}{2\epsilon _0ℓ\left(\kappa x+l-x\right)}$$ c)$$F=-\frac{dU}{dx}=\frac{dQ^2\left(\kappa -1\right)}{2\epsilon _0ℓ\left(\kappa...

Lets go through the example problem until we get to the part I don't understand. Figure 25-17 can be used as a reference to all questions. From part (a) to part (b) we eventually find the charge q on one plate (and by default the charge -q on the other). No problem there. The battery is then...

Potential depends on the charge contained by the conducting plate. So the plate C should change the electric field and hence potential on both plates A and B. This should change the absolute value of potential,but since A and B are still connected to that cell, I think the potential difference...

(a) (b) have intuitive solution but the asymmetry in (c) is confusing.

Summary:: Griffiths problem 8.5 Problem 8.5 of Griffiths (in attachment) I already solved part (a), and found the momentum in the fields to be $$\textbf{p}=Ad\mu_0 \sigma^2 v \hat{\textbf{y}}$$ In part (b), I am asked to find the total impulse imparted on the plates if the top plate starts...

Bit of a random question... capacitors can be a bit weird, in that if we connect one up to a source of EMF and do positive external work to separate the plates of the capacitor, the energy of the capacitor decreases (and instead the work you do plus the decrease in capacitor energy goes into the...

I tried to find logic behind how do we simplified the circuit as given for 2 hours and I unable to find any clue. I can do it just by following rules but I am unable to get intuition. I tried to make sense of it but how can we even make two points as one.

So this is a question from my lab report on capacitance. The aim of the experiment is to find out the relationship between surface charge density and radial distance from the centre of the plate capacitor. And in this experiment I have recorded 5 sets of data, namely r=0, V=4, r=1, V=3.5, r=2...

If so how does the electric field around look like?

Is there any diagram showing the inner workings of the capacitor of a phone? If an old phone becomes less chargeable (takes less time to be fully charged), what happens to its capacitor and the dielectric?

a) the EMF of ℰ induced on The Wire, as a function of the speed 𝑣of the wire you can find it. b) flow induced in the wire𝑖, 𝐶, 𝐵, and are denominated in 𝑙 𝑎 (𝑎= the acceleration of the wire). c) find the magnetic force acting on the wire in𝐶,𝐵, 𝑙 and𝑎. d) 𝑎 acceleration, 𝑚, 𝑔, 𝑙, and are...

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This is the problem I'm working on. So far I know: 1. I am assuming the free charge density is +sigma for the top plate and -sigma for the bottom plate. 2. The electric field from the plates goes from top to bottom plate, in the negative z direction. 3. The electric field of the capacitors...

Most textbooks say that a capacitor whether it be a single one or one in series/parallel should have equal amounts of + and – charges on both plates and that they mostly conclude the + charges attract the same amount of – charges on the other plate without giving any reason. Now I claim that...

Assuming we have an infinite plane capacitor,where the upper plate is charged positively and the bottom layer is charged negatively. Now we know the field outside the capacitor is zero so we can't tell if the positive charge is on the upper plate or the lower plate. But, if we place it inside...

When I try to do Gauss, the permeability is not always that of the free space, but it varies: up to a certain radius it is that of the void and then it is the relative one. How can I relate them? I'm trying to calculate the capacity of a spherical capacitor. The scheme looks like this: inside I...

Hi there, tried doing this question but not sure if what I did for part b is right? Appreciate any help! Thanks

I first attempted to use kinematics, but to find acceleration I would need to find the force either by finding the e-field first and multiplying it with q, or just kQq / r^2. However, I was not given second charge or surface charge density. Is there another way I could go about making the...

This is the problem. If someone asks you this question, how would you solve it? I am finding it really tough to solve when the circuit gets a bit complex. It would be nice if you share what exactly you'll do to solve complex circuits such as this (the algorithm).

I was wondering about , have there been or are there any systems that would use a large capacitance rotary capacitor/s as a mechanism for soft start of larger AC motors and also they would serve as power factor correction devices? The idea is basically simple, say one has a 3 phase motor and we...

In derivations of capacitance it is standard to consider two oppositely charged, infinitely thin sheets. If we construct a Gaussian cylinder across one sheet, we obtain ##E_{1} = \frac{\sigma}{2\epsilon_{0}}## for one sheet, and then we can superpose this field with that from the other at an...

This is a second grade high school problem, translated from my native language. I don't have a problem with calculating, but with understanding the concept. There is an instruction with the assignment that says: The capacitor can be viewed as a combination of two capacitors in series with...

the attached files are a diagram of the circuit. also I believe I figured out how to proof equation (7) but I'm lost on how to proof (8)

There must be something I'm not understanding about capacitors in series. I know that we can treat them as one equivalent capacitor with: (1) with 1/Ceq, (2) same Q as anyone of the capacitors, (3) and add up the Vs for the sum total V across them. If the equivalent capacitor (Ceq) would...