5 votes

Why does the capacitance of a capacitor depend on charge and potential?

In Newtonian mechanics "acceleration of an object ($a$) = force applied on it($F$) / mass if the object ($m$) ". Does that mean m is dependent on $F$ and a as $m= F/a$ ? No! mass is an ...
S K's user avatar
  • 61
2 votes

Why is potential continuous at dielectric conjunction?

$\dots$ the electric field will "jump" at boundary $\dots$ This means that the potential gradient will change at the boundary but that does not mean that the potential changes. Thus a graph ...
Farcher's user avatar
  • 96.2k
2 votes

What is the voltage across the capacitor and the charge it stores

Is it always the case that the voltage across the capacitor = the voltage of the battery? Even though they're in parallel.? It's not "even though they're in parallel," it's because they are ...
Solomon Slow's user avatar
  • 14.6k
2 votes

Why doesn't charge flow from a charged capacitor to an uncharged one when the circuit is open?

When the switch is closed charge does not "migrate" from B to C. The charge on B is held there by the attraction of the charge on A. What does happen is the existing charge on C is ...
Bob D's user avatar
  • 71.8k
2 votes
Accepted

Why doesn't charge flow from a charged capacitor to an uncharged one when the circuit is open?

The answer does appear counterintuitive at first glance - it's often designed that way to test understanding. If B was by itself, its charge would flow to C when the switch is closed. But with the ...
Señor O's user avatar
  • 7,615
2 votes

Why do the electric field vector and displacement vector have opposite directions for a capacitor?

The text book is not saying that the electric field goes from negative charge to positive charge rather is says that the electric field direction is from positive charge to negative charge but the ...
Farcher's user avatar
  • 96.2k
1 vote

Maximum Impedance for LCR series circuit

The answer is very simple. The total complex impedance Z is $$Z = R + jš›šL + 1/(jš›šC)$$ where $R$ is the ohmic resistance, $j$ is the imaginary unit, $š›š$ is the angular frequency, $L$ is the ...
freecharly's user avatar
  • 16.1k
1 vote

Entropy of dielectric in Capacitor?

This is called the electrocaloric effect and para- and ferro- magnetic materials also show similar behavior. It can be shown that, see Eq (5) and the references therein, with $\mathbf D=\epsilon_0 \...
hyportnex's user avatar
  • 18.9k
1 vote

What is the voltage across the capacitor and the charge it stores

After a long time when transients have died out, in a dc circuit an ideal capacitor will look like an open circuit, meaning there will be no current in the capacitor branch of the circuit. That means ...
Bob D's user avatar
  • 71.8k
1 vote

How does the presence of a static electric field affect the normal operation of an antenna (if at all)?

There should be no influence on the RF performance of the antenna unless the electric field is so strong that electrostatic forces would move or deform the antenna, or that air ionization with plasma ...
freecharly's user avatar
  • 16.1k
1 vote

Capacitor discharging connected to power supply AND resistor together

Think about removing the capacitor P from your circuit. You have just capacitor Q and resistor R in series (with switch closed). What happens? As the capacitor charges up the current falls, the ...
Rich's user avatar
  • 829

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