Capacitors Definition and 884 Threads

Hello everyone, Thanks in advance for any wisdom you can offer regarding this matter, I just joined physicsforums.com and am now wondering why I haven't been a member all along... My crudentials: I'm an electrician that went part way through college for electrical engineering, however Its...

Homework Statement Suppose you have a capacitor with capacitance C charged to voltage V and a second capacitor with capacitance C charged to voltage 2V. The two capacitors are connected in parallel. What will be the voltage across the two capacitors after being connected in parallel?Homework...

Homework Statement Four capacitors are connected as shown and connected to a battery to maintain a constant potential difference between points a and b. A charge Q2 = 61.6 μC is measured on capacitor 2. What is the charge on capacitor C3? Homework Equations Q = CV; rules for...

Hello, I googled the difference between polarized and non polarized capacitors and all i found was differences in construction and the material that they are formed from. I want to know why there is 2 types of capacitors, what are the differences (cost, technical, etc), why there is not...

Homework Statement Initially switch is at A, and C1 is fully charged (batter=12volts). C2,C3 are initially uncharged. Then switch is moved to B and the charge is redistributed. What is the voltage across C1? [Answer: 8.00volts] What is the voltage across C3? [Answer: 2.67volts]...

HI, please do not get me wrong, I am trying to grasp and learn when HV capacitors get dangerous and I am confused right now. Your help is extremely appreciated. Caps discharge their energy very very quickly and said THERFORE to be dangerous, but a Van de graaf also discharge its energy...

if two equal capacitor one of then is charged and the other is not.then the switch is closed, half of the stored energy of the 1st capacitor will be lost. if there is a way to move electrons from one of the positive plates to the other positive of the other capacitor,will it require less...

Homework Statement Homework Equations The Attempt at a Solution Working backwards I found that adding C1 (of radius a and b) and C2 (of radius b and c) in parallel gives the answer. Not sure why they can be modeled as capacitors in parallel though..

Homework Statement Calculate the capacitance between A and B in the attached diagram. (Capacitor.png) The Attempt at a Solution I just want to clarify something in my book first: The definition for capacitors in parallel is given as 'the capacitors are directly wired together at one...

Q) In the adjacent circuit, find the potential difference across AB Fine , now i did the charge distribution as follows Now in the first loop (sorry i forgot to mention the points in my image) applying kirchhoffs loop law 10 = q1/8 + q/8 or, q + q1 = 80 Next in the second loop...

Homework Statement A parallel plate capacitor has circular plates of radius 12.0 cm that are separated by a distance of 4.0 mm. The potential across the capacitor is increased at a constant rate of 1300 V/s. Determine the magnitude of the magnetic field between the plates at a distance r =...

Homework Statement Homework Equations The Attempt at a Solution I'm not sure what is being varied here, radial separation between capacitors x = (b-a) or whether the capacitors can slide up and down so as to change the length L of the capacitor..

Homework Statement This is like related to a homework problem, but I'm just curious: If we have two capacitors and two resistors in series, the overall capacitance and resistance does not change regardless of the order, right? Likewise, if they were in parallel (like a resistor + capacitor...

Homework Statement Part A Given 4 capacitors of the same capacitance C, (a) list all values of capacitance you could obtain by connecting up to 4 capacitors. (b) Construct a table with two columns: the first column contains all possible values of capacitance in increasing order, and the...

I really have troubles determining whether a circuit is in series or parallel. Specially when it comes to capacitors, sometimes they draw it horizontally and sometimes vertically and both can occur in one circuit. How for example magically we combine two capacitors drawn like this -l l- and they...

So I'm reading that in a capacitor, an electric field is being manifested between two plates. There are no electrons actually traveling from the negative to the positive plate, correct? There is only an attraction?

I have several questions about capacitor's concepts. Q1)What does battery really do in charging a capacitor? Q2)Uncharged capacitor doesn't mean the plates don't have any charges? Q3)During charging,the developing electric field between the plates does have any effect in charging? Q4)When...

https://www.dropbox.com/s/gvml20bk7435zoa/a.gif I need to calculate the equivalent capacitance of this circuit, but I cannot tell which of the capacitors are in series or in parallel. Can someone explain to me how can we figure this out?

Homework Statement 2 parallel plate capacitors of distance separation d between the plates are connected in parallel of capacitance C_1 and C_2 respectively and charged with a voltage V after that the Voltage is disconnected and a dielectric of κ is inserted into C_2 I) Express the charge on...

I'm currently on the chapter on capacitors in my physics book. I'm starting to get the concept, but everything still isn't crystal clear. I get that you can store charges in two plates, one containing a charge of Q, and the other a charge of -Q. But, would it not also work if the charges where...

I'm taking electricity and magnetism at school and i we are learning about capacitors. I get how they work and what they do. However, i don't see how they're useful. What is their purpose other than storing energy? why not just have the battery supply the energy?

Problem Given the power that is needed to be output by the capacitor - P the length of time that the capictor must give off that power - t the maximum operation voltage that the capacitor can operate at- V the dialectric constant of several materials - ε the breakdown field of those several...

Homework Statement At which location will the electric field between the two parallel plates of a charged capacitor be the strongest in magnitude? a. near the positive plate b. near the negative plate c. midway between the two plates at their ends d. midway between the two plates nearest...

Homework Statement If a 3.0-μF capacitor charged to 40 V and a 5.0-μF capacitor charged to 18 V are connected to each other, with the positive plate of each connected to the negative plate of the other, what is the final charge on the 3.0-μF capacitor? a . 11 μC b. 15 μC c. 19 μC d...

Hello, Suppose we have a battery, and there exists an electric potential difference between the positive and negative terminals, call it, V. When I attach a capacitor to the battery, will begin to charge, if it is initially uncharged. When the capacitor reaches its maximum charge, the phrase...

Homework Statement In Fig. 26-32, the battery has a potential difference of 20 V. http://www.webassign.net/hrw/26_32.gif Homework Equations If Capacitors are in series, then (1/C1) + (1/C2) = (1/Cnew) If Capacitors are in parallel, then you just add them, C1 + C2 = Cnew The Attempt at...

Hello, I've read about capacitors in series from two different textbooks, and both of them seem to implicitly state that the electric potential is different for each capacitor in series. Why is this so?

Hello, I am currently reading about what has been alluded to in the title of this thread. I attached a diagram, as it will be of some help. Okay, in my textbook it says: After the battery is attached to the circuit, the capacitors quickly reach their maximum charge. Let’s call the maximum...

Homework Statement Capacitors C1=13μF and C2=21μF are each charged to 10V, then disconnected from the battery without changing the charge on the capacitor plates. The two capacitors are then connected in parallel, with the positive plate of C1 connected to the negative plate of C2 and vice...

Homework Statement A 2600-nF capacitor is disconnected from the 15-V battery and used to charge three uncharged capacitors, a 100-nF capacitor, a 200-nF capacitor, and a 300-nF capacitor, connected in series. After charging, what is the potential difference across each of the four...

Homework Statement The figure shows three capacitors with capacitances C1, C2, and C3. How are they connected: in parallel or in series? |------| |------| |.....| (middle dots don't mean any thing. they help keep lines in place) |---| |---| |---|Homework Equations Serie...

Recently got hired at a local electric utility and unfortunately my college did not offer a lot of power classes so I am struggling with some things that really come down to how capacitors and inductors interact. I think I have some ideas but am really looking for some reassurance that I am...

So I am having some trouble conceptualizing potential difference, and how to calculate it without integrating the E-Field. My problem is how exactly would you calculate the potential difference between the two plates of a capacitor. When a capacitor is charged up with a battery of voltage V, the...

If I understand it correct,energy of atomic electronic shells fusion cannot exceed energy of their breakdown.For example you need to spend more energy to break down water molecule than you receive energy when you burn hydrogen.Does that mean that energy stored in capacitors could potentially...

I have attached the picture of the circuit. I'm trying to figure out the steady state voltages across the 2 resistors and the capacitor. V_s is given to be 10V DC. At steady state in a DC circuit, a capacitor acts as an open. When that happens, we shouldn't expect any current to flow...

A Capacitor stores energy when it is charging up but what is the intuition behind such a process ? I, in fact, think that as electrons are being stored on one of the plate, positive charge is being build up on the other plate, an electric field is set up as there is a separation of charges, and...

I have some conceptual questions regarding capacitors and dipole antennas. Consider a parallel plate capacitor made with two conducting plates, initially uncharged. If I connect each plate to a different terminal of the battery, charge will start to flow from one plate to another. Consider...

I just finished my last physics class (e&m) and I was pretty intrigued by capacitors and their ability to store charge. I decided to take an electronics class next quarter so I bought a few things including breadboard, capacitor, resistor, diodes, motors, and so on. Now...I have a 50V 1000uF...

If fill mica between the air gaps between capacitors will how? We need consider mica as conductor?

Homework Statement One type of ink-jet printer, called an electrostatic ink-jet printer, forms letters by using deflecting electrodes to steer charged ink drops up and down vertically as the ink jet sweeps horizontally across the page. The ink jet forms 30-μm-diameter drops of ink, charged...

I was wondering if anyone had any insights on how to estimate or discern the potential drops across a capacitor containing three distinct media between the electrode plates. The system is as follows Vo-(+) air gap | binary electrolyte phase | plastic phase (-)The lengths of the air gap is...

Homework Statement Please check the attachment to see all the variables Homework Equations Xl=2*pi*f*l, Xc=1/2*pi*f*c, variation of ohms law The Attempt at a Solution Ok for 5) i found Xl & Xc, then i combined the resistances in parrallel and used ohms law to find I=v/r. My...

I have two questions: 1) Is it in general assumed that the parallel plates of a capacitor are fixed to some surface or is there a force that counteracts the attractive force between the plates whenever one considers a typical problem involving capacitors? 2) Consider a dielectric of length L...

Homework Statement In the circuit shown in the figure each capacitor initially has a charge of magnitude 3.00nC on its plates. A) After the switch S is closed, what will be the current in the circuit at the instant that the capacitors have lost 80.0% of their initial stored energy...

Homework Statement What is the charge on the right plate of C2 long after the switch is closed? 1. CV 2. CV/2 3. CV/3 4. 2CV/3 5. 0 Homework Equations Q = CeqV The Attempt at a Solution Q = 1/3c * 2V so I thought Q = 2V/3C

Homework Statement http://screencast.com/t/9KET4sNSAQWj If the picture isn't showing up, the order of the capacitors is 1 -> 2 & 4 (parallel) -> 3, with a battery in the circuit. There's a dielectric in C2 with k = 2.71. There's a battery with v = 5.33v in the picture. Capacitors: C1 = 11.2 μF...

Homework Statement Two capacitors connected in series store energy U. Now the two capacitors are connected in parallel to the same voltage source and have energy 5U. What is the ratio of the larger to small capacitor?Homework Equations For series capacitors Ceq=C1C2/(C1+C2) For parallel...

Homework Statement Two capacitors, capacitance of 30 μF and 60 μF respectively, each has charge of 50 μF and 70 μF. The capacitors then connected in series. Find the potential difference on each capacitor now Homework Equations Q = CV The Attempt at a Solution I know that the...

By rolled, I mean this kind of basic homemade capacitors: http://www.ehow.com/how-does_4852927_building-a-capacitor.html Kind sirs, I have few questions regarding this kind of capacitor: 1.) Would I still be able to get the 'theoretical free-space' capacitor of the same dimensions using C_o =...

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?