All Questions
123
questions
0
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2
answers
72
views
Cannot catch a minus sign mistake when deriving the ODE for an LC circuit
It's probably a very basic question but I just cannot wrap my mind around it. I'll just try to derive the differential equation for an LC circuit:
According to the law of induction, in a solenoid we ...
- 4,887
0
votes
1
answer
45
views
Voltage drop across an ideal inductor
I was afraid to type the title of the question though there are lot of answers to similar questions. I spent half a day going reading these questions and trying to understand the answers posted and ...
- 65
0
votes
1
answer
90
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Inductors with different directions connected in series
I know that inductors oppose the change of the current. So for two inductors with different direction in series (one in clockwise and the other in counterclockwise), the equivalent inductor is $L_{eq} ...
- 1
0
votes
0
answers
31
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Current sensitivity in transformer scheme with SQUID
I've tried to determine the maximum current sensitivity in this transformer scheme but I'm not sure if my solution is valid. I need to find the relation between the current in the input transformer ...
0
votes
3
answers
61
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Can an inductor increase circuit current?
Suppose there is a simple circuit with a resistor, battery and inductor. The question that came to me is, by opening the circuit breaker, can the inductor be used to oppose and slow down the circuit ...
0
votes
1
answer
47
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Thought experiment: EM fields and coils
Hello Physics Exchange,
I have been thinking a lot lately about EM fields. I thought about something the other day and wanted to check with the experts if my intuition is correct or not. I know this ...
0
votes
2
answers
65
views
Maximum Impedance for LCR series circuit
Impedance of an LCR series circuit can be maximum when either Inductive Reactance or Capacitive Reactance is maximum at an instant of time.
Max Capacitive Reactance is at minimum frequency, and max ...
0
votes
1
answer
35
views
What does "90 degrees ahead of phase" mean in inductance problems?
I've been working on this homework problem and I have determined that the induced EMF on the right coil is sin(x-90). However, I do not understand what "ahead of phase means." When I graph ...
- 101
0
votes
3
answers
69
views
Are there losses in an ideal transformer?
In a circuit with an AV power source $V$ and a zero-resistance ideal coil, the power from the source. $P_{in} = IV$ is equal to the rate of change in the magnetic energy $U_B$ stored in the coil. The ...
- 2,142
0
votes
0
answers
29
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Is AC voltage across transformer pi shifted?
Suppose the voltage in the primary coil in a capacitor be
Vprimary = Vosin(wt)
According to my understanding, as the (AC) current in the circuit increases, the Magnetic flux across the secondary ...
- 153
1
vote
2
answers
76
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
0
votes
0
answers
26
views
Determining the condcutivity of a material by method of contactless resistance caused by putting a sample rod in the inductor of an RLC circuit
I'm doing an experiment where I'm trying to determine the conductivity of a material by putting a sample rod in the center of a coil which is a part of an RLC circuit with an AC generator.
I was told ...
1
vote
1
answer
205
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Current and Magnetic Poles of a Solenoid (Diagram) & Right Hand Thumb Rule
Well, my doubt's pretty elementary.
Firstly I wanted to confirm whether both the cases, as illustrated in the picture, are correct. I've darkened the part of each coil that faces us. Using the clock-...
- 72
2
votes
5
answers
108
views
Magnetic field in a capacitor in a $LC$ circuit
Consider a simple $LC$ circuit in which the charge on the capacitor varies sinusoidally. Current flows in this circuit, changing the charge on the capacitor and hence changing the electric field ...
- 29
0
votes
0
answers
51
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How to find magnetic permeability of a mixed core?
Inserting a ferromagnetic rod into the core of an inductor increases its inductance. If the change in inductance is known, the following equation can be used (or so I assume) to find the relative ...
