Parallel plate capacitor Definition and 182 Threads

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...

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.

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...

I was going through the capacitor lesson in my textbook. In it its written "...both positive and negative plates will produce electric field in the same direction, hence the electric field adds up...outside the plates, electric field is zero since the field due to negative and positive charges...

So electric field tells us the force per unit charge that is felt by a test charge at a distance d from a source charge. So it tells us that the closer the test, or other charge, is to the source charge ,the stronger the interaction, and also that the larger the source charge, the stronger the...

Homework Statement An electron with a speed of 5.0x10^6 m/s is injected into a parallel plate apparatus, in a vacuum, through a hole in the positive plate. The electron collides with the negative plate at 1.0x10^6 m/s. What is the potential difference between the plates? Vi= 5.0x10^6...

Homework Statement My question is: If we have a parallel plate capacitor with 2 parallel dielectrics both taking A/2 of the complete surface, is the total electric charge equal to sum of the electrical charges in the first dielectric and the second dielectric, i.e is qtotal=q1+q2=σ1*A/2+σ2*A/2...

Homework Statement A parallel plate capacitor is constructed with plates of area .0280 m^2 and separation .550mm Find the charge on each plate when potential difference between plates is 20.1V. what separation would be necessary to give a charge of 20 nC on each plate?Homework Equations Im...

Consider a parallel plate capacitor with layers of dielectric between its plates somehow that the interfaces between them are parallel to the plates of the capacitor. If the surface charge density on the plates of the capacitors be \sigma , gauss's law gives D=\sigma which is the same inside...

What would have been if the opposite and equal charge wouldn't have been induce on 2nd conductor in parallel plate capacitor when connected to a battery

Homework Statement Two parallel plates, each having area A = 3558 cm2 are connected to the terminals of a battery of voltage Vb = 6 V as shown. The plates are separated by a distance d = 0.54 cm. 1) What is Q the charge on the top plate? 3.5*10^-9 C 2) What is U, the energy stored in...

Does anyone have any idea how I could begin to examine the field of two conducting plates which are side by side instead of parallel ?

Homework Statement The Attempt at a Solution All I need to know is the acceleration acting on the particle after the potential is applied. v_f^2 = v_i^2 + 2ad (1*10^{-5})^2 = -(1*10^{-5})^2 + 2a(1*10^{-3}) a = 1*10^{-7} m/s2 Is this the correct approach to finding acceleration?

Electrostatics -- 3rd plate inserted into parallel plate capacitor Homework Statement This question is from the book by I.S Grant and W.R Phillips on Electromagnetism. Two large parallel plates of area A and distance d apart are maintained at potentials 0 and V. A third similar plate...

Homework Statement Two circular disks spaced 0.50 mm apart form a parallel-plate capacitor. Transferring 1.70 ×109 electrons from one disk to the other causes the electric field strength to be 3.50 ×105N/C. What are the diameters of the disks? Homework Equations Refer to attachment...

Question taken from Griffiths Pg 185, Problem 4.19: For part (b): -Why are the electric fields the same whether in dielectric or in air? In part (a), they are clearly different! -Why is σ_{tot} = ε_{0}E = ε_{0}\frac{V}{d} -In calculation of capacitance, why is the total charge (\frac...

Homework Statement Two related questions (from Electromagnetics by Notaros) The dielectric of a parallel-plate capacitor has two homogeneous parts, referred to as dielectric 1 and dielectric 2. The boundary surface between the parts is flat and parallel to the capacitor plates. The dielectric...

Hi all "A parallel plate capacitor in which plates of area A are separated by a distance d, has a capacitance C = \frac{Aε_{0}ε_{r}}{d} It is charged to a pd V. Neglecting edge effects, derive an equation for the electric field E in the capacitor, and show that the energy stored per unit volume...

Consider a capacitor with 4 parallel plates and 3 dielectric insulators arranged like this...+I-I+I- The insulator in the center has an equal amount of + and - charge on each side of it so shouldn't the electric field across this insulator be almost zero? If I constructed this capacitor with...

Homework Statement A parallel-plate capacitor C , with plate separation d , is given an initial charge ±Q_{0}. It is then connected to a resistor R, and discharges, Q(t)=Q_{0} e^{-t/RC} 2 (a) What fraction of its energy Q_{0}^{2}/2C does it radiate away? Homework Equations The equations for...

Homework Statement How much charge can be placed on a capacitor with air between the plates before it breaks down if the area of the plates is 5 cm^2. Homework Equations C=\frac{Q}{\Delta V} C=kC_o C=k\frac{\varepsilon _o A}{d} Where "k" is the dialectric constant. The Attempt at a...

I am in process of designing a homemade capacitance sensor and I'd like to have an approximation of the resulting capacitance of the following geometry. The plates are placed on the outer surface of a food grade plastic cylinder. The distance z between their edges is many times smaller than the...

Homework Statement The space between the plates of a parallel plate capacitor is completely filled with a conducting slab.What is the capacitance of the system ? Homework Equations The Attempt at a Solution The capacitance of a capacitor when a dielectric medium is placed...

If you have an infinite non-conducting plate, the electric field just outside is equal to sigma / 2*epsilon. The electric field just outside a conductor is equal to sigma / epsilon. I understand both these results, but why is it than in the formula for the capacitance of a parallel plate...

Homework Statement The parameters of an air-filled parallel plate capacitor are: d = 5mm and A = 500cm2. The charge of the electrodes are Q = 10nC and −Q. Inside of the capacitor in the middle point there is a point charge of 0, 02Q. Find the magnitude of the force acting to the point charge...

Homework Statement I'm asked to find 1)The capacitance 2)The electric field 3)The surface charge density 4)The polarization charge at the interface between the dielectrics. Of 2 set ups. The first one is a parallel plate capacitor which is half filled with a dielectric ##\varepsilon _1## and...

Homework Statement The Attempt at a Solution I know that the E-field is definitely affected by the presence of the space charges. Since one side is positive, the positive charges in the air get pushed towards the negative plate. so Enet = Eplate - Echarges But the thing is...

I am new with the topic Capacitors .I have read that a capacitor can be charged in two ways .One using the battery which I understand .The other is by charging one plate and grounding the other plate .I am not able to understand how this is done . Suppose +q charge is given to a plate ,say...

Homework Statement Q .1 The plates of a parallel plate capacitor are given equal positive charges. What will be the potential difference between the plates? What will be the charges on the facing surfaces and on the outer surfaces? Q.2 Each plate of a parallel plate capacitor has a...

Homework Statement What is the potential energy of an electron in a parallel plate capacitor if kept on the negative plate before being released? Homework Equations 1/2mv^2 = qV = PE Capacitor Energy = 1/2QV The Attempt at a Solution 1/2mv^2 = qV = PE However if I'm not mistaken there's...

Hi, A parallel plate capacitor is charged from fixed voltage, after I cut voltage source. Now, what's happened if I place a Faraday cage inside capacitor (without touch capacitor) ? Capacity changed ? So energy of capacitor changed ?

Hi, so I'm having a little trouble understanding why... you would put a dielectric in between a parallel plate capacitor? I know it increases the capacitance but it does so by lowering the potential difference sooo... The charge is still the same, I believe the potential energy also decreases as...

Homework Statement This is an EM waves class, but we are given the following problem, which seems deceptively simple. I'd like some feedback to see if this is done correctly. Homework Equations Consider a parallel plate capacitor connected with a resistor with resistance R, as shown in the...

Homework Statement If a parallel plate capacitor is charged with charge Q and -Q on its plates, respectively, and then isolated, then we place a dielectric into the space between the plates, does the charge on the plates decrease, or stay the same.Homework Equations U=(QV)/2The Attempt at a...

This doubt is nagging in my mind for couple of days,and its makes the rest of the things so dizzy and confusing.Heres what i thought- What is the electric field at a point inside a parallel plate capacitor? I thought of this-When i place a guassian surface of ,well maybe any...

Electromagnetics -- parallel plate capacitor energy storage Homework Statement A parallel-plate capacitor 0.5m by 1.0m has a separation distance of 2cm and a voltage difference of 10V. Find the stored energy, assuming that ε=εo. If a 200-volt potential is applied in the capacitor, (a)...

Homework Statement A 10 gram pith ball having a charge of 1μC is electrostatically attracted to one of the inside surfaces of a large parallel plate capacitor by an electric field between the plates. The plates are vertically oriented so that the electric field between the plates is...

Homework Statement A 10 gram pith ball having a charge of 1μC is electrostatically attracted to one of the inside surfaces of a large parallel plate capacitor by an electric field between the plates. The plates are vertically oriented so that the electric field between the plates is...

Homework Statement A vacuum parallel plate capacitor is given. Its plates are of thickness h, width L (in the plane of the figure) and their distance is D. The plates of the capacitor are perpendicular to the plane of the figure, which is at the same time the symmetry plane of the...

Homework Statement Use Gauss' law to find an expression for the electric field within a charged parallel plate capacitor with two layers of dielectric materials (?r1 and ?r2). (See attached image, this is for question 2a). The Attempt at a Solution My approach would be to split the...

Homework Statement In a region of space between the plates of a parallel plate capacitor 14.0 cm apart, the electric field is 5.50 V/m everywhere. What force would be exerted on a point charge of charge value 2.50 C located 1 cm below the positive plate? 1 cm above the negative plate...

Homework Statement Hi everyone, I'm new here at posting but have found this forum very useful in the past. I have hit a snag with a capacitor problem... any thoughts? Assume you have a parallel plate capacitor separated by one cm of air and one cm of a dielectric with a dielectric constant of...

Ok I took E&M about 3 years ago and decided I needed to review it. I'm up to gauss' law and am getting confused about one thing. If you have two infinitely long oppositely charged plates, solving for the total e field inside is done by making two gaussian surfaces that enclose each plate. Doing...

If you have a simple circuit with only a battery and a parallel plate capacitor with a dielectric, what exactly happens when the battery is turned on? Also, if the voltage of a capacitor with a dielectric is less than the EMF of the battery, what happens to the rest of the voltage? One...

Homework Statement How does a parallel plate capacitor work (conceptually)? Also how does each plate get charged? Homework Equations The Attempt at a Solution

Homework Statement A 5800-nF parallel plate capacitor is connected to a 14-V battery and charged. What is the charge Q on the positive plate of the capacitor? Homework Equations C = Q/V The Attempt at a Solution This looks like a very simple question. The capacitor is fully charged...

Why is it that the field magnitude between two plates in a parallel plate capacitor is given by q/(εA)? In my book it is stated that one plate is of charge +q and the other -q. But if each plate is charged, wouldn't you need to account for the electric field produced by both places making...

Homework Statement a parallel plate capacitor of 10pF is charged to 10kV ( air dielectric). It is then isolated from battery.The plates are pulled away from each other until distance is 10 times more than before. what is the energy needed to pull the plates. Homework Equations c=εA/d ...

Homework Statement See figure attached for problem statement, as well the solution. Homework Equations The Attempt at a Solution I'm confused as to how he is writing these equations from the boundary conditions. What I understand as the boundary condition for D is, \hat{n}...

Homework Statement If one were to consider a parallel plate capacitor with a distance d between them connected to a battery and a vacuum space between the plates. Will the integral form of Gauss' Law to any closed surface between the plates that does not cross either plate hold? If not, what...