All Questions
54
questions
2
votes
0
answers
1k
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Finding the voltage across an inductor when opening the switch [closed]
Well, I've the following circuit:
In the circuit I want to find the voltage $\text{V}_{\text{Y}_1}\left(t\right)$ as a function of time, after I open the switch (this switch was closed 'forever' ...
- 21
1
vote
2
answers
137
views
Current in the inductor at $t=0$
$L_1 = 5H, L_2=0.2H, M=0.5H, R_0=10 Ω$, and $i_g=e^{-10t}-10 A$. I need to find $i_2$.
I've started with DE
$$i_2R_0+L_2(di_2/dt)+M(di_g/dt)=0$$
and solved it for $i_2$, so $$i_2=0.625e^{-10t}+Ce^{-...
- 111
0
votes
0
answers
281
views
Exponential fit in Origin doesn't converge
I am using a data treatment program called Origin, wich I think many of you are familiar with. The data I have is time vs voltage in the resistor of an RL circuit.
The expression that describes the ...
0
votes
2
answers
218
views
What happens to a system of capacitors when a dielectric is inserted into one of them?
sorry for my English.
While doing some homework I've stumbled upon this "circuit":
the system is connected to the same potential difference through a generator that is connected to points A ...
- 55
6
votes
3
answers
1k
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Physics olympiad question about a charge capacitor
This is problem 1463 from the Russian magazine Quant.
Unfortunately my Russian is not good enough, so I apologize if the translation of the problem contains errors.
Problem. Inside a flat charge ...
- 417
-2
votes
1
answer
294
views
Finding the current in a light bulb [closed]
I am doing this practice problem where it asks me to find the current through the light bulb at two different temperatures. The problem I am having is that I cannot find out how to do the problem with ...
- 111
0
votes
2
answers
23
views
Magnetic energy in coil at time $t$ after circuit being hooked up
"A coil with inductance L = 50 mH and R = 600 ohm is coupled in series with a resistance R = 200 ohm to a battery with the voltage 12 V. How great is the magnetic energy in the coil at the time t = ...
user180617
0
votes
1
answer
629
views
Transformer universal EMF equation derivation
At this Wikipedia page, we've that the 'Transformer universal EMF equation' looks like:
$$\text{E}_{\text{rms}}=\frac{2\pi\times\text{f}\times\text{n}\times\text{a}\times\text{B}_{\text{peak}}}{\sqrt{...
- 291
0
votes
1
answer
248
views
How to derive and write Kirchoff loop law for circuits including capacitors?
Consider a circuit like the one in the picture
Where $V_0$ is an electromotive force.
How do I write Kirchoff "loop law" for circuits like the one in picture (i.e. with capacitors)?
Here is the ...
- 2,617
2
votes
2
answers
2k
views
Faraday's law in circuits with multiple loops and different magnetic fields
I'm confused about the application of Faraday's Law in to situations with a circuit made of two loops that enclose two different changing magnetic fluxes.
Which of the two is correct?
The emf in each ...
- 2,617
0
votes
1
answer
107
views
Will there be any current induced in a purely capacitive circuit?
Will current be induced in a purely capacitive circuit if a magnetic field B is present perpendicular to it and a movable conducting wire completing the circuit is moving with a velocity v.
Just want ...
2
votes
1
answer
1k
views
How do I show for an ideal transformer $M^2=L_1L_2$?
I've been stuck on this problem for about an hour.
In an ideal transformer, the same flux passes through all turns of the primary and of the secondary . Show that in this case $M^2=L_1L_2$, where $...
- 5,371
1
vote
1
answer
640
views
Faraday's Law: Current loop and proton
A single circular loop of wire with radius R carries a large clockwise current I(loop)=I0, which constrains a proton of mass M and charge e to travel in a small circle of radius r at constant speed ...
- 21
2
votes
1
answer
1k
views
Current in an RC circuit inside in a magnetic field
Does my question make any sense?
Context: The capacitor is charged with charge $Q_0$. There is a magnetic field $B=B_0 \hat{z}$ perpendicular to the monitor's screen. The length of the (AB) wire is $\...
- 365
2
votes
0
answers
42
views
ODE envolving current [closed]
I have to do this exercise:
9. The current $I(t)$ at time $t$ flowing in an electric circuit obeys the differential equation
$$I''(t) + RI'(t) + I(t) = \sin \omega t$$
where $R$ and $\...
- 21