All Questions
17
questions
1
vote
2
answers
78
views
Telegraphers' equations for lossy transmission line when $R$, $L$, $G$, and $C$ are frequency dependent
The telegraphers' equations are commonly written as
$$\frac{{\partial v(z,t)}}{{\partial z}} + R\space i(z,t) + L\frac{{\partial i(z,t)}}{{\partial t}} = 0$$
$$\frac{{\partial i(z,t)}}{{\partial z}} + ...
- 11
1
vote
2
answers
358
views
Relation between resistance, capacitance and resistivity
I recently learnt that for a resistive medium, $RC = ρε$ where $R$ is the medium's resistance, $C$ is the capacitance, and $\rho$ is the resistivity. Now, I am able to prove that this is true in the ...
- 301
0
votes
0
answers
83
views
How do you determine the electromotive force when the negative plate of the capacitor is connected to the positive terminal?
$\newcommand{\d}{\mathrm{d}}$We have a square wave source with period $T$ and voltage $V_0$ connected to a circuit which is has a resistor of resistance $R$ in series with an uncharged capacitor of ...
- 221
2
votes
3
answers
1k
views
Why do resistors in parallel with uncharged capacitors get eliminated from the circuit?
I was doing a problem where I was asked to find the current in an R-C circuit 'just after' the switch had been closed i.e at t = 0. All of the capacitors are initially uncharged. Could someone explain ...
- 155
0
votes
0
answers
111
views
How to find the canonical equations of the RLC circuit
First, I consider the LC circuit with an ion in the capacitor, which is like this:
The current $I$ can be derived easily by using Shockly-Ramo theorem
\begin{equation}
I = -\frac{qp}{dM} + C\dot{U} \...
- 68
0
votes
2
answers
46
views
Capacitor, charges, resistance and much more
I am not able to understand if charges are circulated to charge the capacitor even if the circuit is open, then if we connect a bulb in between the capacitor and cell then that charge charging the ...
0
votes
3
answers
101
views
Capacitors charging, resistance much more?
I am overwhelmed by the amount of doubts i am having regarding this device
(CORRECT ME WHEREVER I AM WRONG PLEASE)
First things first if we connect a capacitor using two ideal wires (for each plate) ...
0
votes
1
answer
67
views
Can it be the some energy will remain after long time? Capacitors and resistors [closed]
My question is pretty simple, but I'll have to describe the problem in order to ask it:
We have a an RC circuit as we can see in the picture.
The given details are:
the resistance of the resistor $ R $...
- 213
0
votes
1
answer
794
views
Resistor and capacitor in series
If you put a resistor and a capacitor in series with a 9V battery so that the resistor is in the wire going out from the positive terminal of the battery to a plate of the capacitor.
In my opinion ...
- 323
1
vote
4
answers
472
views
What do we mean by Inductive and Capacitive Reactance?
In the topic of pure A.C. Circuits, we have $I = V/\omega L$ and $I = V/\omega C$.
I know that $\omega C$ & $\omega L$ does the work of Resistor, but what does it mean and what do we mean by ...
- 329
0
votes
1
answer
1k
views
Inductor vs. capacitor discharging - how a low resistance affects the two?
I'm confused about why the two discharging patterns occur in regards to resistance. If I am understanding correctly:
An inductor: A lower resistance means that it will take longer for the inductor to ...
- 1,177
1
vote
5
answers
4k
views
What's the difference between conduction current density and source (impressed) current density in an $RC$ circuit?
My electromagnetics textbook has a picture of an $RC$ circuit with a current source.
As you can see, there are three current density vectors, $J_i$, $J_c$, and $J_d$. The book labels them as follows:
...
- 11
0
votes
1
answer
172
views
Imaginary component in capacitive reactance
This is a trivial question in first year but, unfortunately, this popped up in an elementary yet compulsory lab experiment.
The capacitive reactance is defined as $$X_{c}=\frac{1}{\omega c}$$
The ...
- 889
0
votes
2
answers
525
views
What actually goes on in RLC circuit?
I already have difficulty understanding how each of the RLC circuit elements work individually as it is, and I have no idea how they work simultaneously in an RLC circuit.
My schoolbook represents the ...
- 49
1
vote
2
answers
137
views
Why does electrical impedance have as many parameters as it has?
The impedance of a circuit is written:
$$ Z(R,L,C,f) = R + j ( 2 \pi f L - \frac{1}{2 \pi f C} ). $$
What is the line of thinking that frequency, resistance, capacitance, and inductance are the only ...
- 161