How to Find the Voltage Across a Capacitor in an RLC Circuit?

AI Thread Summary
To find the voltage across a capacitor in an RLC circuit, use the equation V(t) = i(t)R + (1/C) ∫_0^t i(u)du + L di(t)/dt, as per Kirchhoff's laws. If the circuit is powered by a constant voltage source, the capacitor voltage will equal the battery voltage after a sufficient time. For alternating current sources, the same equation applies, but requires solving for specific conditions. The configuration of the components, whether in series or parallel, affects the calculations. Understanding these principles is essential for analyzing RLC circuits effectively.
dancingmonkey
Messages
11
Reaction score
0
My question is how do I find the voltage across a capacitor? I have an RLC circuit with a switch and battery. It only gives me the values for the battery, L, C, and R.

My main question is, is there an equation or something to find the voltage across a capacitor?
 
Physics news on Phys.org
Is it connected in series? If so, according to Kirchhoff, V(t) = i(t)R + (1/C) int_0^t i(u)du + L di(t)/dt

Solve that equation and you are done.
 
If the battery is a constant voltage source (direct current), the voltage across the capacitor should be that voltage if you wait a sufficiently long time (typically a few seconds will do the trick, if the inductance is not too high).

If it is an alternating current source, you will have to solve the equation posted by Termotanque.
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
Back
Top