# Tag Info

## New answers tagged capacitance

0

Why does a capacitor charge only upto the voltage of the source? Step by step: (1) When the capacitor voltage equals the source voltage, the voltage across the resistor in the series RC circuit is zero (2) By Ohm's Law, the current through the resistor must be zero too. (3) Because it is a series circuit, if there is zero current through the ...

0

Here's how I would convince myself of the correct answer. Draw a circuit diagram showing the voltage source, resistor, and capacitor. (I assume it's in a simple series circuit?) Next, write out Kirchhoff's loop rule. You should find something like $V_\text{source}-V_\text{resistor}-V_\text{cap}=0$. Note that this equation is true at any time, not only for ...

0

The solution for the plate capacitor is an approximation for separations much smaller than the plate area scale. Therefore it will be unusable if the distance between the plates becomes large. One thing the approximation does not take into account is that even if the distance between the plates goes to infinity or one plate is removed, one plate will still ...

1

In the absence of supporting information, it's hard to say where to start. Do you have a circuit diagram, at least? Typically one would identify certain nodes at which the voltage(s) are known, then trace all electrical paths to figure out which capacitors have that node in common (suggesting parallelism), and which capacitors are connected in sequence on ...

2

I first show that we can write $$\Phi_j=\sum_{k=1}^NP_{jk}Q_k\tag{1}$$ for a given configuration of conductors; then it it will be straightforward to deduce $$Q_i = \sum_j k_{ij}V_j$$. To prove $(1)$ we draw on two concepts: principle of superposition, and the uniqueness of the solutions of electrostatics problems. Consider $N$ isolated conductors. ...

2

I think that "because of linearity" should be read as "because of the superposition principle" (which does rely on the linear response of the dielectrics). You do not need to go into the detail of the field distribution: As in your example, set all potentials to 0, except for $V_i$. Denote this situation by $(i)$. The corresponding charges on each ...

2

Batteries produce a charge difference across the terminals as a result of a chemical reaction. A chemical gets changed into another one. Even in a rechargeable battery a chemical change takes place that is reversed. An electrolytic capacitor uses chemistry to create a thin layer with an electric field across it. The thinner layer than a "regular" capacitor ...

4

This is true, however the bending is not much until one comes closer to the edge so it is usually neglected or too small to depict. Here's what I get when I simulate the system: This is the same system as a vector plot:

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