Capacitor Definition and 1000 Threads

Hi there, new to this website so please bare with me if I break any rules and let me know for future. I am a maths and physics tutor but occasionally I come across a question I just cannot work the answer for. In this case I know the answer but I can't get to it. 1. Homework Statement...

Is it possible to make a device that could store all the heat put into it, until it builds up and amounts to something significant? It would basically be a capacitor for heat. I was thinking that since if it touched anything cooler than it, heat would drain out, so it would have to be in a...

http://<a href="http://imgur.com/UwulXqg"><img src="http://i.imgur.com/UwulXqg.png" title="source: imgur.com" /></a>[/PLAIN] 1. Homework Statement Find equivalent capacitance of this formation from a to b, C1=4.1 uF, C2=6.86 uF, C3=5.03 uF, C4=5.92 uF http://imgur.com/UwulXqg Homework...

Homework Statement A parallel circuit like that in the figure forms the tuning circuit for an AM radio. If the inductor has a value of 8.6×10-6 H, what must be the maximum and minimum values of the variable capacitor if the radio receives frequencies from 590k Hz to 1670k Hz? a) Maximum C? b)...

What methods could I utilise to find the individual values of the components - resistor, inductor and capacitor - of a series RLC circuit using an oscilloscope, signal generator and 10 ohm resistor. Where each component can be isolated in order to find the voltage etc. I've already found the...

Homework Statement The electric field strength is 2.50×104 N/C inside a parallel-plate capacitor with a 1.20 mm spacing. An electron is released from rest at the negative plate. What is the electron's speed when it reaches the positive plate? Homework Equations F = eE = ma vf2 = vi2 + 2ad...

Homework Statement For the circuits shown, each utilizing an ideal diode (or diodes), sketch the output for the input shown. Label the most positive and most negative output levels. Assume ##CR > T##. The input waveform is given by: I have re-drawn all of the circuits in my solution, which...

Suppose to have a BJT Common Emitter amplifier like the one below: Now, if we send a signal ##V_{in}## with a frequency belonging to the midband frequency interval, we can consider ##C_1, C_2,## and ##C_E## as short circuit. Questions are: 1) What is the effect of ##C_E## (excluding its role...

Homework Statement Attached Homework Equations The one given in the hint (as attached) for voltage across capacitor wrt time. P=V^2/R The Attempt at a Solution I just wanted to know whether I've gone about this question in the right way. For the first part I simply rearranged the voltage...

Homework Statement A parallel plate capacitor with plate area A = 100 cm^2 and plate separation of d = 5mm is connected to a 120 Volt power supply and allowed to fully charge. a) Calculate the capacitance, stored charge, electric field midway between the plates and potential energy stored...

I've been looking all over and to my great surprise have not be able to find an answer to this question. What is the capacitance between to parallel plates if one plate is larger than the other? For example, the capacitance between a 1" diameter plate and a 4" diameter plate. Thanks.

Hello, Please I would like to know how the resistance of the plates of a capacitors work? Is it the same as a resistor? If yes, is there electric field like inside a resistor? Thank you

If there is a parallel plate capacitor with plate area, A, plate separation, d, and a slab of copper of thickness, b, is inserted exactly halfway between the plates. How to find it's new capacitance, C', and new potential difference, V' ? Answer: V' = E(d-b) and C' = εA / (d-b) I...

How exactly do the electrons move from the capacitor to the rest of the circuit? Do they fly between the capacitors plates, or can they only travel where there is a wire connection? (I.e., if a small chunk of our circuit looks like this: A-------| |-------B can an electron start from A, go to...

Suppose we have a circuit with two capacitors connected to each other, C1 and C2. C1 is charged and has a potential difference of 5 V (V1=5V), but C2 is not charged (V2=0) Apparently it is known that the potential difference of these two capacitors will want to reach equilibrium. So V1=V2...

Homework Statement The switch is initially open and the capacitors are uncharged. The applied potential difference Vab = +210V. a.) What is the potential difference Vcd? b.) What is the potential difference across each capacitor when the switch is closed? c.) How much charge flowed through the...

Homework Statement a conducting spherical shell has radius R and potential V. If you want, you can consider it to be part of a capacitor with the other shell at infinity. you compress the shell down to zero size while always keeping it spherical,while a battery holds the potential constant at...

Homework Statement [/B] I have two capacitors: 1-Farad capacitor A, and 9-Farad capacitor B. In state (a), I charged A with 1 Coulomb of charges, as depicted in figure (a). In state (b), I paralleled A with B, by doing this I discharged A, as depicted in figure (b). I try to find the total...

Homework Statement Two identical capacitors Ca and Cb each of capacitance 6.60 http://lon-capa.mines.edu/adm/jsMath/fonts/cmmi10/alpha/100/char16.png F are connected in parallel across a CONSTANT total electric potential difference of 480 V. A dielectric slab of dielectric constant 4.65 can...

Homework Statement I have browsed similar threads and have only found more confusion. My question is if I have two parallel plates with an area A = 1m^2 and they are separated by a distance d = .03m. Each has a charge of Q and -Q respectively where Q = 1nC. I want to find the electric field...

Homework Statement [/B] A circuit is constructed with five capacitors and a battery as shown. The values for the capacitors are: C1 = C5 = 3.9 μF, C2 = 3.9 μF, C3 = 5.7 μF, and C4 = 4.2 μF. The battery voltage is V = 12 V. What is Q5, the charge on capacitor C5? Homework Equations C=Q/V...

Homework Statement An inductive load is connected to a 120V (rms), 60Hz AC source. The load draws 5.0 kW at a power factor of 0.81 (lagging). You need to improve your power factor to 0.96 (lagging) by adding a capacitor. What is the Capacitance needed (in uF)? Homework Equations P/|S| =...

In the figure given the capacitance for the two pair would be same. Can anybody please explain me how the charge would be distributed across each plate? I think that the middle plate being isolated should have +Q on one side and -Q on other, but how would be the charge distribution about the...

Hello I need some advice about electrostatic levitation concept and am trying to make an experimental setup for that. Consider two parallel plates with the same sign charge and the bottom plate is fixed in place. Therefore there will be a repulsive force which pushes the upper plate...

[Since "the universe is a capacitor" got zero hits on Google, I'm reasonably sure this is wrong, but I'm just not sure why it's wrong. Thanks in advance for your response.] ----------------------------------------------------------------------------------------------------- Batteries and...

Homework Statement This problem apparently has a simple solution if you are good with circuit theorems but no matter what i try or how i combine them, it's just impossible. Given a circuit on the picture, and circuit parameters E3=12V,R1=1kΩ,R2=30Ω,R3=150Ω,R6=200Ω, if it is known that current...

Homework Statement "A series combination of capacitors must always be smaller than the smallest individual capacitor." This is the statement that I am trying to validate, but I am stuck. Homework EquationsThe Attempt at a Solution [/B] I know that if you have a circuit that consists of a...

Hey PF, I have a thought experiment that's been driving me nuts, here it is: I take a parallel plate capacitor charge it up to a steady state and then isolate / disconnect it from the electrical system leaving me with two charged parallel plates. I then hook up a power supply to two corners of...

Hello, I have made a capacitor with two aluminium foils separated with paper dielectric with, dielectric constant (K) = 3.8 for paper material paper thickness, D = 0.1mm = 1e-4 m plate or foil area, A = (12.1 x 8.3)cm = 0.010043 m air permitivity, Eo = 8.85e-12 F/m Calculated capacitance = (K...

I have only just found out about inductors, and am trying to figure out how a circuit with an inductor and a capacitor could change dc current to ac current. With the set up of the circuit, would it suffice just to have the dc supply with a 'gate' that stops/allows through the dc current with a...

Can anyone explain the use of capacitor in a shock pen

I have heard that a capacitor increases the voltage of output in a circuit can anyone explain it

Homework Statement A charged parallel plate capacitor with plates in the x-y plane and uniform electric field ##\mathbf E = E\hat z## is placed in a uniform magnetic field ##\mathbf B = B \hat x## i) A resistive wire is connected between the plates in the ##\hat z## direction, so that the...

Homework Statement For the following bridge rectifier you are asked to find the dc output voltage for the following errors: a)the capacitor is an open circuit b)one of the diodes is open c)the electrolytic capacitor is connected with reverse polarity The Attempt at a Solution My attempt is...

How is the current that pushes electricity through the space between the two plates of the capacitor called?

Hello everyone! I need help identifying a capacitor. It reads 12.C29 Its very small, maybe .25" long. It's on an audio input board from my Kenwood A/V receiver. Thanks for the help! Josh

Homework Statement The attached graph shows the relationship between time and voltage for three resistors. A capacitor is discharging current through three "separate" resistors. How resistors might be positioned in a circuit to give rise to the graphs.Homework Equations V = IR CR = $$\uptau$$...

I've recently taken to understanding capacitors and capacitance. If I understand them correctly they are what store electrical charge or electrical energy. I don't quite understand their purpose though, do they keep the breadboards from overloading with power but keeping little pockets of...

i am having trouble finding out all the names given to the components in this circuit. Also i am struggling to find the names to the two different parts of the circuit. can anyone help me please?

Hello... kindly help me out in designing of power capacitor to improve the power factor as the given load is 950 KWatt and power factor is 0.7, as i want to improve the power factor to 0.92 then what formula i should use to design the capacitor as the Voltage line to line are 400Volts

Homework Statement A cylindrical parallel plate capacitor of radius R is discharged by an external current I. The total electric field flux inside the capacitor changes at a rate dΦe/dt = I/ ε0. What is the strength of the resulting magnetic field B(r, I) inside the capacitor at a radial...

1. The problem statement, Dielectric plate is placed in capacitor to the half(picture) and it can freely move. Capacitor consists of two parallel plates and is isolated. Consider two cases: a)charges on plates are constant, b)voltage is constant. What happens in each case? 2. Homework...

If both the plates of a capacitor are connected to positve voltage, (but has a potential differnce between them) will the capacitor be charged? And how?

They are rated at 1V. Suppose they are in a 40V circuit, and rated to handle 40V. Would they then hold 40x the charge? I tried to calculate it base on electron repulsion, but I remember reading that electrons are not like gasses: they all go to the surface of the material in counter intuitive...

Suppose AC current is shooting into a wire, and the wire is attached to a bulk piece of metal off to the side of it, kind of like a ground, but not as deep as a ground. Wouldn't the bulk piece of metal work kind of like a capacitor and smooth out the voltage a bit? Everywhere I Google, I see the...

Homework Statement A voltage source given by ##v_s(t)=25cos(2\pi\times10^3t-30^\circ)## is connected to a series RC load. If R = 1MOhm and C = 200pF, obtain an expression for ##v_c(t)##, the voltage across the capacitor. Answer known to be: ##v_c(t)=15.57cos(2\pi\times10^3t-81.5^\circ)##...

Homework Statement Three conducting capacitor plates are kept horizontally, above each other with a gap 'd'. If a charge ##+1\mu C## is kept on the middle plate what is the charge on the plates? Homework Equations (This question is theoretical) The Attempt at a Solution My textbook gave the...

Hi guys, I'm new to this forum and I just started working on my first coilgun. I've watched several tutorials on how to build a coilgun but all the capacitors they use in the coilguns are electrolytic capacitors. The capacitors don't deliver as much energy as the car audio capacitors. I'm...

Homework Statement After a capacitor of capacitance ##C_1## is charged up to a voltage ##V_o##, the Battery is removed from the circuit. Another capacitor of capacitance ##C_2## is connected in series with the capaciotr ##C_1##. Find the charge on each capacitor after equilibrium is attained...

I cannot find info on how to read capacitance on all these ceramic capacitors in my lab. I probably have 50 different capacitors but cannot find instructions on how to read most of them, any instructions I find on how to give the multiplier or whatever seems to apply to only a handful. and its'...