How many electrons on a Capacitor calculation

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Discussion Overview

The discussion revolves around calculating the number of electrons on a capacitor, exploring the relationship between charge, capacitance, and voltage. Participants also delve into concepts related to capacitor charging, time constants, and the behavior of voltage in circuits.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant inquires about the calculation of the number of electrons in a capacitor and references the relationship between charge, capacitance, and voltage using the formula Q=C*V.
  • Another participant confirms the calculation of charge using the provided values of capacitance and voltage.
  • Questions arise regarding the charging behavior of capacitors in relation to series resistance and the nature of exponential processes in electrical transients.
  • Participants discuss the equation Vc = Q / C, with some expressing frustration about needing to learn fundamental equations.
  • There is a question about the sum of voltage drops in a closed circuit, with varying levels of depth in responses provided by participants.
  • One participant suggests that the static electric field is conservative, leading to a zero net work done in a closed path, while another expresses concern about the readiness of the questioner for such an explanation.

Areas of Agreement / Disagreement

Participants generally agree on the basic principles of capacitor charging and the equations involved, but there are differing levels of understanding and readiness to engage with more complex concepts. Some questions remain unresolved, particularly regarding the deeper implications of voltage drops in circuits.

Contextual Notes

Some discussions involve assumptions about participants' prior knowledge and readiness to tackle complex topics, which may limit the clarity of explanations provided.

Who May Find This Useful

Individuals interested in electrical engineering, physics students, or anyone looking to understand the principles of capacitors and circuit behavior may find this discussion beneficial.

ENE
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Hello,
How to find number of electronics in capacitor?
as 1 coulomb and 1 Amp has 6.25x10^18
on what they depend?
Is this correct..?
Q=C*V
C=47uF and V=12V
Q=47*10^-6*12=5.64*10^-4 Coulmb?
 
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ENE said:
How to find number of electronics in capacitor?

The number of electrons in a capacitor is given by Q=CV, which you've calculated correctly.
 
Thanks.

I don't understand this graph
How the capacitor will charge with series Resistance?

rc2.gif
 
Hello,
I got
a. The rate of charging is typically described in terms of a time constant RC.
b. The electrical transient phenomena in capacitors and inductors are exponential processes
tcons.gif
voltage across the capacitor
how we get exponential here?
rc15.gif
 
The voltage on a capacitor is Vc = Q / C.

Note: you copied images from two different circuit explanations and that's causing confusion. The "Vb" in the first image is "Vs" in the second image.
 
  • Like
Likes   Reactions: ENE
i have to learn this equation?
 
ENE said:
i have to learn this equation?

Oh, the horror! The horror!

Yes, you have to learn it.
 
  • Like
Likes   Reactions: ProfuselyQuarky
in electrical engineering how man equation are there?
 
  • #10
ENE said:
voltage across the capacitor
how we get exponential here?
proxy.php?image=http%3A%2F%2Fwww.electronics-tutorials.ws%2Frc%2Frc15.gif

We solve the differential equation for the circuit. See for example

http://web.mit.edu/molly/Public/circuits-b.pdf

and scroll down to page W6-6. This uses Q as the variable, not V, but you can change variables using Q = CV if you prefer.
 
  • #11
Hello,
Why The sum of the voltage drops∆Vi , across any circuit elements that form a closed circuit is zero.??
 
  • #12
fizzle said:
The voltage on a capacitor is Vc = Q / C.
Vanadium 50 said:
Oh, the horror! The horror!

Yes, you have to learn it.
ENE, that's an awfully basic equation, you needn't worry :woot:
 
  • #13
ENE said:
Hello,
Why The sum of the voltage drops∆Vi , across any circuit elements that form a closed circuit is zero.??

The answer to this is kind of in-depth and I don't feel you're ready for it at the moment.
 
  • #14
ENE said:
Hello,
Why The sum of the voltage drops∆Vi , across any circuit elements that form a closed circuit is zero.??
The static electric field is a conservative field. So the work done on a closed path is zero.
Do you understand the relationship between work and potential difference?
 

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