# Questions tagged [capacitance]

The ability of an object to store electric charge.

265 questions with no upvoted or accepted answers
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17 views

### Large Equivalent series resistance for polarized capacitor

Consider a standard RC circuit with a $100 k\Omega$ resistor and a capacitor. Here's some issue encountered during the lab. When using specifically a polarized capacitor($20 \mu F$), in addition of ...
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### Ferroelectric energy storage

Let say we have a ferroelectric capacitor which is capable to store 1 joule of energy. Then we remove charged plates and remain only fully polarized ferroelectric. Are there some ferroelectrics which ...
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### Circuit breaker and capacitance

I have a problem with knowing witch capacitor to use in a circuit because I am working on installing main circuit breaker where it is needed for 220 Volt AC current to be turned in to a lower current ...
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### Conduction current for parallel-plate capacitor

I am reading Sadiku's Elements of Electromagnetics and here is the proof given to show that conduction current = displacement current for parallel-plate capacitor. Displacement current: \begin{align*}...
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### Proper utilization of Ampereās Law

I am tasked with finding the magnetic field due to a bus bar, which seems to have the exact same set up as Problem 7.62 in the fourth edition of Griffiths' textbook on Electrodynamics. To which I ...
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### capacitor and electrostatic field

Is there any electrostatic field around the leads of a charged capacitor? Let's take just the negative one. If I take a piece of tissue and put close to that terminal it will attract or repel the ...
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### Derive the formula for a capacitive voltage divider?

I've seen the derivation for a resistive voltage divider, Vout = Vin * R2/ (R1 + R2). For a capacitive divider, Vout is reported as Vout = Vin * C1/ (C1 + C2) - for example see https://en.wikipedia....
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### About the capacitance of the capacitor

I would like to ask two questions here , 1. When a capacitor reaches to its maximum limit charge starts leaking and it ionises the air atoms . Well is it true ? As I'm not able to get an convincing ...
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### capacitance of cube skeleton

A cube of 12 capacitors is very common problem. find capaciance accross edges we get 12c/7. But lets say we have 8 more capacitors involved now. that is we have capacitors at all sides of cube and ...
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### Does an uncharged capacitor in a non uniform electric field have a voltage difference at its terminals?

If an uncharged capacitor was placed in a dc field would there be a voltage difference developed on its terminals related to the different locations of the two surfaces in the voltage field? Would the ...
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### Capacitance of spherical capacitor when inner sphere is earthed

Consider the following derivation: (Source: http://www.ncert.nic.in/html/learning_basket/electricity/electricity/electrostatics/inner_sphere.htm) If a charge of $+Q$ coulombs is given to the outer ...
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### rotating capacitor question

Imagine a simple setup. I have a copper disc and another copper element held close to the disc at one of it's sides, this element is stationary but the disc is rotating, the part between the disc and ...
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### Error of capacitnace measurement using a multimeter

physics stack exchange Many multimeters have a setting for measuring capacitance. The multimeter I have has a precision of four significant figures, or in other words, it returns the value in the ...
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### How do multi-meters measure capacitance?

Many multimeters have the ability to measure capacitance along with the ability to measure AC voltage, DC voltage, current, resistance ... The only equations I am aware of that determine capacitance ...
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### Why didn't my Capactive Wireless Power Transfer work?

Today I had the delight of setting up a bipolar capactive wireless power transfer (CWPT) circuit for a school experiment. Disappointingly, it did not work. It was set up just like in the diagram ...
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### Capacitor, stored energy versus reactive power

When an AC voltage U is put onto a loss less capacitor C the capacitor will require a certain reactive power Q (current 90 degress out of phase with the voltage): $Q=UI = \omega C U^2$ in VAr (Only ...
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### Limit charge of electronicāhydraulic analogy of a compartment

I am doing a mathematical model of an hydraulic system and I am using an electronic-hydraulic analogy. Normally a compartment is simulated with a capacitor. But in my system I can apply a big ...