Capacitors Definition and 884 Threads

Homework Statement The power factor of a circuit has to be improved from 0,6 to 0,9 by adding capacitors. Originally, it only has an inductor L, a resistence R and a generator V. The circuit requires an active power of 3000 VA, and that should remain the same. Vef = 220V. The Attempt at...

i assume on my input bias line the capacitors to ground are there to decouple the ac contribution/nosie that might arise on the DC bias. Why do i consistantly see two caps in parallel, something like a 10uF and a.1uF forming a 10.1 total. One is 100 times bigger than the other, why not...

Im not sure if this should go here, but. . . Im building a motion detector. I have the breadboard hooked up the following way using an op amp, a potentiometer, photocells, resistor and led. http://img6.imageshack.us/i/breadboard.jpg/ So it seems to work fine, but I wanted to...

If two parallel plates are facing one another and one of them are moved without opening the switch, what's the difference with moving the plates after opening the switch?

Homework Statement A 100pF and a 400pF capacitor are both charged to 2kV. They are then disconnected from the voltage source and are connected together, positive plate to negative plate. (a). Find the resulting potential difference across each capacitor (b). Find the energy lost when the...

Hi, I have a supply for biasing a photomultiplyer tube in a plessey ratemeter. In the supply there is a voltage multiplyer of the Villard cascade type, with a filter after it. The voltage multiplyer is supplied with a 9kHz supply of 300v p-p. We replaced the original capacitors, which...

Hello all, I have been boggled by this problem the whole day today. Lacking a charge electrometer, I am limited in the ways I can test my theories. I'll explain the problem in small steps: Suppose you have two capacitors, each with the same capacitance. Let's say, 1 farad each. You...

lets say we have these capasitors http://img130.imageshack.us/img130/4368/fpff.png and we know Vab,C,C1,C2,C3 etc whats the method to find Q,Q1,Q2,Q3 etc ? thanks

Homework Statement A 2.0-microfarad capacitor is charged to 250 V. It is then connected to an uncharged 1.0 microfarad capacitor through a 2.2 ohm resistor, by closing switch S in the figure . Find the total energy dissipated in the resistor as the circuit comes to equilibrium. Hint...

Homework Statement I have a system of capacitors set up in a combination of parallel and series connections. The first question(part a) asks me to find the total capacitance of the combination. The second question(part b) asks me to find the total energy stored in the system of capacitors...

Homework Statement Four capacitors are connected as shown here: http://i4.photobucket.com/albums/y103/thepastryman/HWa.jpg (a) Find the equivalent capacitance between points a and b (b) Calculate the charge on each capacitor, taking delta Vab= 15.0V note: the actual numbers are not the same...

At t=0 the switch S is closed with the capacitor is uncharged. ..... 3M ohm... 102 micro F --------------^^^^^--------ll------------- l l l ... s...<----i--->......l l-------l i-------/.--------------------------l 17...

Homework Statement Two capacitors of 34.0 μF and 125 μF are separately charged to 126 μC and 250 μC, respectively. They are then attached in parallel so that the + plate of one goes to the - plate of the other, and vice versa. Determine the final voltage across the two plates. Homework...

I have been trying to do some research, but the more I search, the more confused I get (praise physics for that one). In anycase, I know that a charge moving through a magnetic field creates a current, so let's say we have an initially charged loop moving through a quasi-uniform magnetic field...

Homework Statement Capacitors of 11.1uF and 1.9uF are charged as a parallel combination across a 333V battery. The capacitors are disconnected from the battery and from each other. They are then connected positive to negative plate and negative to positive plate. Find the resulting charge on...

Homework Statement A 50 \muF capacitor is being charged from a 6V battery via a 100k\Omega resistor . what is the initial charging current? after a period of time, the charging current is 30\muA. what are the pd's across the resistor and the capacitor at that moment? how much charge has been...

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...

Homework Statement Hi, I'm trying to solve this problem on MasteringPhysics: This circuit is given, and it says C-eq for the circuit is 9.22 microfarads: http://img143.imageshack.us/img143/3475/walker4ech21pr118.jpg The question is to find C in the figure knowing C-eq is 9.22...

Can a DC choke (inductor) filter be used in a resonant circuit with a capacitor? If connected in series with a capacitor will the two resonate, or will the signal passed be half wave? I thought all inductors can be interchangeable but some have certain applications such as DC applications.

So i decided to get this teach yourself kit on how to use capacitors and resistors and a stamp chip or something like that. Its working great and I'm making LED's flash and stuff...but it uses a serial interface to load the program I make into the stamp. My question is, if i have a real thing...

HELP!Capacitors in circuit Hey guys, I have a short question here. If a resistor and a capacitor are connected in a series, it takes 2 seconds for the capacitor to to have a voltage of 2V, what happen to the voltage across the original capacitor if another same resistor is added in series? The...

dear revered members, could u people let me the know the role of capacitors in the ignition system of automobile engines? how they eliminate sparking in ignition system 2) how they reduce voltage fluctuations in power supplies 3) how they are used in tuning radio circuits thanks in advance

hi, this is a basic conceptual question. Assume two identical capacitors of capacitance C without any leakage. potential difference across one capacitor V volts and the other capacitor is 0 volts. now the energy stored on the first cap is 1/2*C*V*V and there is no energy stored on other...

For parallel capacitors a resistor is needed in the loop when I run a simulation but I haven't seen this in any circuits, is it not needed in a real circuit?

Could someone explain to me the meaning of the following concepts: 1. Filtering out AC: is used to reduce the ripple of a DC power supply. 2. Filtering out DC: Only time-varying signal will pass through a capacitor. The circuit on either side of the capacitor can be at different DC...

I realize Biefeld Brown is a verboten topic on this forum but I believe the admins overlooked the anomalies sections in some NASA studies when coming to that decision. In the http://gltrs.grc.nasa.gov/reports/2004/CR-2004-213312.pdf" tests, in the Observations section it states: After...

Homework Statement Two capacitors are connected in parallel to a battery with voltage of 28V. Let C_1 = 9.0 \mu F and C_2 = 4.0 \mu F . Suppose the charged capacitors are disconnected from the source and from each other, and then reconnected to each other with plates of opposite signs...

Homework Statement An electric field of a capacitor is defined by the following equation, \vec{E} = \frac{\rho_{s} \hat{a_n}}{\epsilon} = \frac{Q\hat{a_n}}{A\epsilon_r\epsilon_0} where \vec{E} = (\frac{\rho_s}{\epsilon})\hat{a_n} Question I understand the first equality, and reviewing...

Statement: Capacitors can be used to store energy or to filter signals. Some examples include filtering out AC [used to reduce the "ripple" of a DC power supply] or filtering out a DC. In filtering out a DC, only time-varying signal will pass through a capacitor. The circuit on either side...

Statement Capacitors can be used to store energy or to filter signals. Example, filtering out AC is used to reduce the "ripple" of a DC power supply. Also Filtering out DC: Only time-varying signal will pass through a capacitor. The circuit on either side of the capacitor can be at different...

The more rapidly voltage across a capacitor changes, the more current will flow (the higher the frequency, the greater the current). Questions I was wondering, does the statement above deal specifically with AC circuits by the statement Or does this statement apply to DC circuits also...

Homework Statement Figure P26.26 shows six concentric conducting spheres, A, B, C, D, E, and F having radii R, 2R, 3R, 4R, 5R, and 6R, respectively. Spheres B and C are connected by a conducting wire, as are spheres D and E. Determine the equivalent capacitance of this system. Homework...

dear members, when a positive charge is given to a metal plate say A, negative charge is induced on the nearby plate B(say) due to electrostatic induction. the presence of negative charge reduces the potential of the plate which increases the capacitance of A by the relation c=q/v. my question...

I have some questions about the energy stored in capacitors. Looking in Physics books, there are two equations which govern the amount of energy stored in capacitors: Energy in Joules (Watt*Seconds) = .5 * Q^2/C Where Q is the charge in couloumbs and C is the capacitance in Farads...

i dismantled a Remote controlled car for its parts and i saw on the electric motor some small capacitors. thats a diagram i know what a capacitor is but in this instance what is its actual purpose? help me please Cheers Demson

There are no electric fields outside of a charged capacitor as they are canceled out due to superposition, right?! So why is there a flow of current when a cable is connected to both ends of the capacitor? I was told that there might be an E field in the wires. How come? Where does it come from?

MMC capacitors exploding on my tesla coil, I need help! Im in a tight spot. I just recently built a decent sized tesla coil. Everything works flawlessly except that my capacitors are melting. They don't fail but they emit flames or they arc, (its hard to tell). Then after inspecting the...

REVIEWING OLD TEST and.. don't understand why you use the full distance. Homework Statement pretty much there's a home made capacitor made by two pie pans 3.5 cm apart. V is given Q is given, the question asks: calculate the electric field halfway between the plates Homework Equations...

I am not sure if I have full understanding of capacitors energy, because I found a contradiction in solving one problem. The problem is: - If an uncharged capacitor connected to another fully charged capacitor in parallel, what will be the new charge distribution on both capacitors...

Homework Statement 2 capacitors of equal capacitance one charged to potential V, and other completely discharged. when the are connected in parallel what would be the potential of each one of them. Homework Equations E=1/2 (C.V^2) The Attempt at a Solution as they are connected in...

Hi I'm new here and I just would like to ask for help regarding our surge suppression system. Our surge supression system is designed to eliminate transient voltage spikes on the 3 phase AC lines to protect the SCR pucks on the scr system. The surge supression system consist of a 3 phase...

Homework Statement A 2.00 \muF capacitor is initially connected to a 12 Volt battery. In a separate circuit, a 4.00 \muF capacitor is connected to a 30 Volt battery. The capacitors are then disconnected from their respective batteries and connected to each other (positive sides are connected...

[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...

potential difference in parallel -- capacitors Two capacitors C1 = 3 µF and C2 = 9 µF are connected in parallel across a 11 V battery. They are carefully disconnected so that they are not discharged and are reconnected to each other with positive plate to negative plate and negative plate to...

An electron beam is send perpendicular onto an electric field between two capacitor plates. The electrons got their kinetic engergi by being accelerated through a potential difference V. The potential difference between the capacitor plates are also V. The distance between the plates is d, and...

If a current enters the negative terminal of a polarized capacitors, does the negative plate have to be fully charged before it passes through to the positive plate.

Homework Statement a capacitor C1 2.4uF charged to a voltage of 880V and a second capacitor C2 4.0uF charged to 560V. They are disconnected from their batteries and their positive plated and connected together, and their negative plated are connected together. What will the final voltage and...

Homework Statement If I have a circuit in which the capacitor is the large disk device and for each value of separation=d, calculate the half-life of exponential decay? Homework Equations The Attempt at a Solution What is the formula to do this?

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.

Homework Statement See attached PDF for circuit.The arangement of capacitors is attached to a voltage source. Each of the 4.0uF compactors stores a charge of 6.0uC. What charge is stored on the 6.0uF capacitor? What is the voltage of the source. Homework Equations Q=C(V) [b]3. The...