Capacitors Definition and 884 Threads

Homework Statement hey A 2.21 uF capacitor is charged by a 20.0 V battery. It is disconnected from the battery and then connected to an uncharged 3.60 uF capacitor (Fig. 17-29). http://www.webassign.net/giancoli5/17_28.gif Determine the total stored energy at the following points in...

Homework Statement Find the equivalent capacitance between points a and b for the group of capcitors connected as shown below. http://img250.imageshack.us/img250/7816/40ha4.th.png Homework Equations Series/Parallel combinations. The Attempt at a Solution I don't get how the...

We've been studying capacitors in series in my physics class. I have a problem tonight and I know the answer, I just don't know how to get to it. The problems is as follows: Find the voltage V1 across the first capacitor. Express your answer in terms of V.

Ok here a scanned photo oh my worksheet for physics. I tried and used what I knew for equations to solve. After looking at other sample problems, I am not sure how to find part b and c of the problem. I think I went wrong somewhere. Could someone take a look and guide me in the right direction...

Homework Statement A parallel-plate capacitor has an area of 5 cm^2, and the plates are separated by 1mm with air between them. The capacitor stores a charge of 400pC. a) What is the potential difference across the plates of the capacitor? b) What is the magnitude of the uniform electric field...

Homework Statement (Note: This is the fourth part of a single question, but it's the only part I'm having trouble with. Don't worry, it's not as simple as Q/V. :smile:) "What is the potential difference between a point midway between the [circular, parallel] plates [which are 1.43 x 10-4 m...

Homework Statement A parallel-plate capacitor has plates with an area of 445 cm2 and an air-filled gap between the plates that is 1.51 mm thick. The capacitor is charged by a battery to 575 V and then is disconnected from the battery. There is 4.311536113 x 10 ^-5 J of energy stored in the...

Homework Statement A 10.0 µF capacitor is fully charged across a 10.0 V battery. The capacitor is then disconnected from the battery and connected across an initially uncharged capacitor with capacitance C. The resulting voltage across each capacitor is 4.00 V. What is the value of C...

1. Capacitors C1 = 4.0 µF and C2 = 2.0 µF are charged as a series combination across a 95 V battery. The two capacitors are disconnected from the battery and from each other. They are then connected positive plate to positive plate and negative plate to negative plate. Calculate the resulting...

If you have two parallel plate capacitors side by side and the electric field in one is constant. If you vary the electric field in the other, will it interfere with the electric field that was constant?

My physics textbook kinda offhandly says capacitors can be charged to higher potential differences than the battery used to charge them and uses a camera flash as an example, however it doesn't say how this is done. What it does say is attaching a capacitor to a batter in a simple circuit will...

In the following schematic, will the RC time constant be the same for all capacitors using the equivalent resistance of all the resistors? When I plug it into pspice or electronics work bench, it has that the First capacitors voltage as a function of time will always be twice as much as the...

if anyone could help me on this it would be much apreciated, thanks :smile: . Question: A capacitor was joined across a digital voltmeter and charged to a p.d. of 1V. the p.d. was then measured at 20s intervals and at t=30s a resistor (R=1.5 mega ohms (1500000ohms)) was connected across the...

I'm supposed to show that while a capacitor is being charged, the energy flows into the region between the plates at the same rate as the electrostatic energy in the capacitor increases. I'm not sure exactly what is being asked of me... are there formulae for these? I feel stupid.

I picked up a good and cheap AC motor that came with its own capacitors <not wired in though> The capacitors are these http://www.weisd.com/store2/NTEMRC370V7R5.html and this is the diagram on the motor http://foxhole.kicks-ass.net/diagram.jpg" Now I tried putting this together but with no...

Consider a two identical capacitors connected in parallel and connected to a battery. The battery is removed and then a dielectric is inserted between one of the capacitors. Why will charge flow from one capacitor to the one with the dielectric? I know the "potential differences in the...

If I have a cube made out of capacitors, that's one capacitor for everyside for a total of 12 capacitors. Each capacitor is C=4.71 pF. How would I even begin to go about finding the total capacitance?

Hi, I am new to this website. I am having troubles in designing a common source amplifier with a voltage gain, Av=26 dB (no bypass capacitor) and a gain of 40 DB (with a bypass capacitor) and a frequency of 100-1000HZ. Can anyone please guide me to calculate the value of the bypass capacitor...

Good day everyone. Please help with these questions. The circuit is a series of 3 capacitors with a battery. C1 = C C2 = 2C C3 = 3C How do you find the voltage across the first capacitor in a series of 3? How do you find the charge Q on the first capacitor? How do you find the...

I don't know how to start solving attached problem (3.126 from Irodov) because I can't identify any series or parallel connection between capacitors. I came to an idea that I should "break" capacitor C3 into two capacitors and then get two series and one parallel connections. Any ideas?

Hello guys. Please look at this, it's a VERY SIMPLE problem and I've almost solved it, but sth is not right... It's a simple problem but i am confused regarding the method that I'm supposed to use to solve this kind of problems. So the problem is: V1 , V2 , V3 and V4, E1, E2 are given. They...

Hello peeps, I am currently studying capacitors and simple electronic circuit design, but I am getting the feeling I am not quite fully understanding things because i keep forgetting key concepts and how they fit together in an abstract sense. (please forgive the long post, its an attempt to...

Hi, When capacitors are connected in series then why charge remains same on each capacitor and why voltage differs on each capacitor? Regards, Rizwan Khalil 923214120424 :smile:

Ive tried so many different ways using the formula for series capacitors and Q=CV and I've had no luck solving this problem. There must be some rule (or trick) I am missing involving combing C12 and C13 that I am completely missing. Can anyone offer any insight into solving this problem?

A 50 pF capacitor and a 200 pF capacitor are both charged to 2.6 kV. They are then disconnected from the voltage source and are connected together, positive plate to positive plate and negative plate to negative plate. Find the resulting potential difference across each capacitor. I can find...

Can anyone help me out with this? I like your word picture of the capacitor circuit. I've added GND and Vsupply to complete the circuit. I've apppended numbers for each plate and wire. I will be referring to each plate/wire/air numbers throughout the message. GND - wire1 - plate1 - air1 -...

Anyone know of a place that sells 10 farad capacitors rated at 20k volts

Question asks: Two spherical conductors of radius 0.01m are placed with their centres 0.1m apart. Calculate the capacitance (C) of this system. I can't do it like a parallel plate capacitor can i? and its not a traditional spherical capacitor is it? So I'm going to have to do it the long...

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...

if there are two capacitors in series and the capacitance of one is known how would i find a value for the other?

I have a question that has confused me a little, A circuit is set up with a 10v battery,a 100 micro farad capacitor and a variable resistor. The capacitor is left to charge with the switch closed. After the switch is opened the variable resistor is adjusted to maintain a current of 100...

A 10 micro farad capacitor is fully charged by connecting a 24v battery. How much energy is stored in the capacitor? How much energy would be required from the battery to charge the capacitor to the 24v level? Explain why the answers are different.

Two capacitors in series are charged by a 12.0-V battery that has an internal resistance of 1.00 ohm. There is a 5.00-ohm resistor in series between the capacitor, as shown in this figure: What is the time constant of the charging circuit? I know time constant, tau, equals R*C, but I...

Capacitors, Hard Problem Four identical capacitors are connected with a resistor in two different ways. When they are connected as in part a of the drawing, the time constant to charge up this circuit is 0.67 s. What is the time constant when they are connected with the same resistor as in part...

A battery of potential V stores charge q on a combintation of two identical capacitors. What are the potential difference across and the charge on either capacitor if the capacitors are (a) in parallel (b) iin series? I know the answers to these questions but I'm trying to understand the...

A capacitor, a resistor, and another capacitor is connected in series. The first capacitor, C_1, has an initial charge of Q_0, and C_2 is initially uncharged. The switch is flipped at t=0, what is the charge on each capacitor as a function of time? So I thought Q_1 =...

Hello everyone, I'm confused on why I'm missing this problem. Here is my work and problem: http://suprfile.com/src/1/25o5ux/lastscan.jpg Any ideas? I know you add up capitors in series like (c1)(c2)/(c1+c2) in parellel c1 + c2 +...+cn

Silly question, but I can't find the answer anywhere in my notes. When you have a capacitor with two parallel slabs of dialectric (equal thickness, different dialectric constants) in between the plates of a capacitor, would you find the capacitance by linear superposition (I wouldn't have...

From Griffiths again! A large parallel plate capacitor with uniform surface charge \sigma on upper plate and -\sigma on lower is moving with a constant speed v. Q1]Find the magnetic field between the plates and also above and below them. My work: For a surface charge distribution: \vec K =...

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...

I am having problems with these two questions - Two capacitors are identical, except that one is empty and the other is filled with a dielectric ( = 3.70). The empty capacitor is connected to a 18.0 V battery. What must be the potential difference across the plates of the capacitor filled...

any ideas on solving this? (the capacitors are initially charged) I have some ideas but `im not sure which one is correct... I know that Q remains the same between C1 and C2, so that V1C1 + V2C2 = v1'C1 + V2'C2. From there, i don`t know if i can do the same thing for capacitors C2 and C3. I...

hey guys, i did these problems out of my book for review and it does not give me the answers. So if you could please, tell me which ones I've got incorrect and if you don't mind explaining and writing down the correct answer for the wrong answer will be awesome! Thanks in advance. (BTW, I think...

Does anyone know the purpose of the capacitors circled in red in the file attached? What are their functions in the circuit? Thanks!

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...

Hello. I have a brain fart and this combination circuit has me stumped. Here is a crude representation of the circuit. I had no problem finding the total capacitance (1.34uF), but the second part asks you to find the charge on each of the capacitors, assuming that the potential difference...

I got a question that reads: Supoose a 10khz signal with an amplitude of 1 volt is applied across a 1k(ohm) trdidyot snf s 0.25 microF capacitor which are connected in series. What is the voltage drop across the capacitor? I tried to use the equation Vc(t) + Vco*cos(omega*t) in which i got...

Hello, I've read an EMP subject on this site a few minutes ago, it' didn't help me anything at all. My buddy had built an EMP with Capacitors and no explosive materials, how would i do it? Im thinking of building one, without explosives, because that's just too dangerous and not a smart...

Hello, I was hoping to get some help with this problem.. Find the equivalent capitance between points a and b for the group of capacitors connected as shown in the following figure if C1=5.00µF, C2=10.00µF, and C3=2.00µF. I appreciate the assistance. :smile: ~Val [diagram attached]

A small plastic ball of mass 6.70×10-3 kg and charge +.0150 uC is suspended from an insulating thread and hangs between the plates of a capacitor. The ball is in equilibrium, with the thread making an angle of 30.0° with respect to the vertical. The area of each plate is 0.0200 m^2. What is the...