Capacitors Definition and 868 Threads

*If at any point I say something incorrect or its clear I don't have the right understanding of something, please point it out and correct me. I need to be sure I'm understanding it all correctly. So please don't answer unless you're willing to read this entire post* So I know capacitors in...

I have no problems with part a). I used the formula for capacitance and determined the charges to be 0.00125 coulombs and 0.002 coulombs. The solution in the book is the same. For part b) my initial thought was that the charges will redistribute themselves so that each capacitor get the same...

Firstly, I'm given this complicated circuit as shown below. What I have to do first, is to simplify it, which I will need help in checking. One question here: It's not possible to simplify this by adding resistors in series and capacitors in series am I, right? Or is it possible in this case...

Hi there, So as far as I know, after long time, current doesn't flow through the resistor That means the voltage drop across the capacitor is equal to the EMF of the cell = 9V So will the charge be ##U = 0.5CV^2## = ##0.5(10)(81)##? Answer appears to be wrong, not sure what I am doing wrong here.

Homework Statement: Help me please Homework Equations: Q=CV

Hi all. I have another exam question that I am not so sure about. I've solved similar problems in textbooks but I have a feeling once again that the correct way to solve this problem is much simpler and eluding me. Especially because my answer to a) is already the solution to c) and d) (I did...

Hello, In regards to this relay, TQ2SA-1.5V Panasonic 2 Form C AS Single side stable, 1.5VDC 2A DPDT NON-LATCHING SMD Relay https://www.mouser.com/ProductDetail/769-TQ2SA-1.5V PDF 1 of Relay PDF 2 of Relay (specifically pages 5-6) is attached at the bottom as a pdf file. I was previously told...

Summary: I need to build an asymmetric capacitor, but the mathematics of electromagnetics become too tough, do you have any info that can help? Appreciate it! Hello, I am an undergraduate student in engineering and I want to build an asymmetric capacitor, so I need electromagnetics which I...

What if you put two RC circuits in parallel?

I already did part a and got the correct answer of 4.8 microC. However, I am unsure how to approach part b, where the switch is closed and apparently the two capacitors end up with different charges. For part b, since there is a path between the two capacitors, I don't know if I am able to...

I suspect that at first the electrons on the other side of the plate in the capacitors are pushed to the light bulb that is the plate becomes more positive to compensate for the increase of electron on the other plate. Was this right? And can anyone refer me to a study or law regarding it?

Hello, I am using this little audio amplifier with my Maximite computer: https://www.amazon.com/dp/B07MQ44KLP/?tag=pfamazon01-20 I know that it's a best practice to use capacitors on the audio output from amplifier chips to filter out any extra DC current. I am under the impression that the...

Homework Statement Question: https://imgur.com/a/EmGDW87 Homework Equations Q =VC V = IR The Attempt at a Solution I don't understand how the capacitor C_2 is in parallel with R, which would dictate that they have the same p.d, but then again the circuit is in stead state and so no current...

I have been struggling to figure this question out lately and could use some help setting it up correctly. As shown in the figure, V = 9.0 V, C1 = C2 = 27.2 μF, and C3 = C4 = 13.6 μF. What is the charge on capacitor 4? I have tried using the summation of charges and then multiplying by the...

--> Hi, I am reading about the capacitors. I have read that the capacitors block DC and behaves as open circuit in DC while short circuit in AC. The reason behind this is the charging and discharging of the capacitor. What is my perception about it, I will mention about it. " During the DC...

HiI was reading about capacitors and potential energy. But the equation seems counter to how i thought. For potential energy you have: U = Q^2 / 2C or U = CV^2 / 2 But doesn't this suggest you lose potential energy the more capacitance you have? Since in the first equation as C increases U...

Homework Statement In the given circuit at t=0 S is closed then at time t, i1/i2 a) is constant b) increases c) decreases d) first increases then decreases Homework Equations V=IR, Q=CV The Attempt at a Solution At t=0, capacitors act like closed switches, so I2=2I1, where I2 and I1 are the...

Homework Statement Homework Equations Vf+(Vi-Vf)e-t/RC Tau = RC The Attempt at a Solution [/B] Normally, I would use the eq'n mentioned above to find Vr in an RC circuit. However, this second capacitor is throwing me off. Is there a new equation I should use? How do I think about this...

Homework Statement Homework Equations The Attempt at a Solution So you need to find the voltage across node D while the capacitor is charging, so it is going to be related to the voltage of the capacitor, so a function of time, so you need to come up with the equation for Vc(t), which I...

So I'm interested in adding a bank of capacitors to help reduce the initial load on my batteries when accelerating from a stop but my current set up uses regenerative braking. My electrinics are this order, Motors, VESC, BMS, 10s5p Li-ion pack. If I add capacitors between the bms and vesc to...

Homework Statement So I need to find the equivalent resistance for the following RC circuit to calculate the time constant, but I got stuck in terms of finding out the equivalent resistance. Homework Equations V = IR The Attempt at a Solution So the thing I am not sure on is how do you...

Can someone tell me what is the advantage of using the combination instead of a single capacitor? The same total power would be dissipated?

If we directly connect the two plates of an ideal charged parallel-plate capacitor, a spark will generate. What is the exact reason of spark?

If we make far away the two plates of an ideal parallel -plate-capacitor, which are connected to a battery, the stored energy decreased according to the energy consideration because capacity decreases while the voltage between the two plates is unchanged. Therefore, according to the energy...

Homework Statement Working through Purcell (among others) as fun applied math/math modeling refresher. But, I have struggled all week in establishing from first principles that the potential/field/distribution for a configuration of two capacitive disks of radius 1 and separation s along the...

Homework Statement Between the plates of parallel plate condenser having charge Q,a plate of thickness t1 and dielectric constant k1 is placed.In the rest of the space,there is another plate of thickness t2 and dielectric constant K2.The potential difference across the condenser will be...

Homework Statement A negative charge of mass m enters into the field between two deflecting parallel plates with length 'l' separated by distance 'd' with a velocity 'v'.Assuming electric field to be uniform,find the maximum charge so that it will not hit a plate Homework Equations Kinematic...

Why is the electric potential of an electron in a capacitor measured from the negative plate and not the positive plate here? This is from Liboff Introductory quantum mechanics 1st(current is 4th) edition: I don't understand why the distance z is measured from the bottom plate if the...

Homework Statement If you put a capacitor in some circuit, why exactly do the conductors that form the capacitor have equal and opposite charge? This seems to be assumed in many cases. Homework Equations Is it possible for the conductors to have different magnitude of charge?

Homework Statement The figure shows part of a complete circuit. The potential at point A is greater than that of B by 19 volts what is the potential difference in volts across the three microfarad capacitor? Homework Equations All relevant to electric circuits The Attempt at a Solution From...

Homework Statement Is the expression Energy density= ## \frac{1}{2} \epsilon_o E^2## true for all capacitors or just parallel plate capacitor? Homework Equations all electrostatic related formulas The Attempt at a Solution Its just a simple question so...no attempts needed

Homework Statement [/B] I want to build a power bank capable of holding 10,000 joules of energy, is portable (can fit in a palm and is lighter than 1kg) and safe (does not short circuit, break down or catch fire easily) I cannot use batteries, only super capacitors What are some problems that...

Homework Statement A capacitor stores 7.9 x 10-2 C of charge when connected to a 6.0-V battery. How much charge does the capacitor store when connected to a 9.0-V battery? Homework Equations PE=CQ/2 The Attempt at a Solution QV^2=CQ^2 (7.9 x 10-2)(6)/2 = Q(9) C= .05 C [FONT=verdana]

Homework Statement A parallel plate capacitor has a capacitance of 7.8 μF when filled with a dielectric. The area of each plate is 1.5 m^2 and the separation between the plates is 1.3 x 10-5 m. What is the dielectric constant of the dielectric? Homework Equations C= (K(8.85E-12)A)/d The...

Homework Statement They give the following circuit. Each capacitor is 50*10^-6 [F], the Resistors are 2[Ω], and the Voltage is 5[V]. In the first step the close only the 1st switch and let the capacitor to be charged. I've found that the charge is 2.5*10^-6 [C]. (using the equation Q = V*C)...

Homework Statement We consider two capacitors with the unknown capacitances C1 and C2. If one connects the capacitors in series and applies a voltage of 100 V, finds that two positively charged plates in total have the charge 1.5 · 10-4 C. If one switches the capacitors in parallel and again...

I'm not really sure if this is even scientific but while calculating how much energy is stored in electromagnetic coils and capacitors, pretty much the same formula is used: For electromagnetic coils it's U=0.5LI2 For capacitors it's U=0.5CV2 Why I think they're the same is that in a sense L to...

Homework Statement I have initially a capacitor with capacitance ##C_1## with charge ##Q_1>0## and energy ##U_1>0##. I put another capacitor ##C_2## with no charge ##C_2=0## in parallel with the first. We assume this is an ideal circuit. The charge will distribute to both capacitors and the...

Hello everyone, I have a RC helicopter that crashed recently and its receiver board was damaged. Two capacitors were dented (as you can see in the picture) and the antenna base moved a bit. I straightened the capacitors which can be seen in the second picture. After crash: After my...

Homework Statement I was going through this PDF on my own to review for my AP Physics C E&M exam: https://apcentral.collegeboard.org/pdf/ap-physics-c-e-m-frq-2017.pdf?course=ap-physics-c-electricity-and-magnetism I was also watching this video (which discusses the solutions): The part I am...

I have two isolated plates A and B, kept parallel to each other. Now I give charge +Q to the plate A, it will redistribute itself as +Q/2 on the outer plate A and + Q/2 on the inner plate A. Right? Now this will induce charge -Q/2 on the inner plate B and +Q/2 charge on the outer plate B...

Homework Statement A circuit contains a capacitor of capacitance C, a power supply of emf E, two resistors of resistances R1 and R2 , and a switch S2 . Resistor R1 is in series with the power supply and R2 is in parallel with the capacitor and the power supply. S2 switches the branch that...

When capacitor is leaking ie, when charge is leaking or when it is discharging then will there be any magnetic field between the parallel plates of capcitor?

I have a decent understanding of power factor caps, (far from perfect) but I’m not as clear on surge caps. Surge caps store transient voltages and discharge back into the system? Why are they tied to ground? And do they also provide capacitance in the motor circuit they are tied to providing...

A couple of months ago I was troubleshooting a blown fuse on a power factor correction capacitor in a 4160v motor starter. While I was working through it I noticed that my DMM (fluke 289) would charge the capacitor to a certain degree while on the Ω function. The current from the meter would...

Homework Statement Homework EquationsThe Attempt at a Solution First I calculated equivalent capacitance between R and M . The two 2μF capacitors are in series . Their combination is in parallel with the 1μF capacitor . Their equivalent capacitance is 2μF . Now I found equivalent...

Homework Statement Homework Equations C = Q/V The Attempt at a Solution Q1 = Q2 C1*V1 = C2*V2 2*V1 = 5*V2 V2 = 2/5*V1 V1+V2 =100 7/5*V1 = 100 V1 = 71.4 V Can someone verify my working? Thanks!

Homework Statement Homework EquationsThe Attempt at a Solution I considered N=2 . Two similar charged capacitors are joined in series i.e positive plate of one is joined to negative of the other . If I consider that there is no movement of charge since both the capacitors are similar and...

Homework Statement Homework EquationsThe Attempt at a Solution I will name the top left capacitor A , bottom left capacitor B and right capacitor C . Before the switch is closed , charges on A and B will be 20 μC each and that on C will be 40 μC . After the switch is closed ,both A and B...

[mod note: thread moved from homework forum] I have this Mouser voltage regulator https://www.mouser.com/ProductDetail/STMicroelectronics/L7912CV/?qs=sGAEpiMZZMug9GoBKXZ75xbXFDWiKqpmvrbz5I0HaKg%3D Wired according to datasheet https://www.mouser.com/ds/2/389/l79-974159.pdf see insert photo...