The electric-circuits tag has no wiki summary.
5
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4answers
2k views
Resistor circuit that isn't parallel or series
What's the equivalent resistance in this circuit (between points A and B)?
3
votes
2answers
304 views
The role of resistor in e.g. an AND gate
What is the role of the resistor in e.g. an AND gate like this one? :
One often sees lots of resistors in electric circuits, but I haven't really understood their role.
1
vote
1answer
870 views
RC Circuit , Calculate Time Constant
Given this diagram:
With S1 switch closed and S2 switch left open, I am trying to find the time constant
Relevant equations
I know τ = RC for a basic circuit, but how would you calculate it for a ...
-2
votes
1answer
200 views
what is the proper way to connect two light bulbs in a circuit? in series or parallel?
What is the proper way to connect two light bulbs in a circuit? in series or in parallel and why?
My thought is that it's better to hook them in parallel, since if we take into account Ohm's Law, the ...
3
votes
1answer
368 views
General integral to find resistance
My question is: is there a simple and truly general equation for the resistance between two electrical equipotential surfaces?. Obviously, if so, what is it, and if not, why? It would be very ...
3
votes
0answers
234 views
Turn-on delay time for Laser diode
Do you know any simple explanation on the reason why the turn-on delay time on a laser diode is reducing while we increase the bias current?
Turn on delay,is the time that the laser needs from the ...
0
votes
1answer
903 views
Battery Calculations [closed]
I have been given the following statistics for a battery and I have been asked to find the
1) battery capacity in Wh
2) volumetric energy density in Wh/cm3
3) gravimetric energy density in Wh/kg.
...
9
votes
3answers
301 views
Current in a simple circuit
I was going over my notes for an introductory course to electricity and magnetism and was intrigued by something I don't have an answer to. I remember my professor mentioning, to the best I can ...
1
vote
0answers
74 views
Simplifying a biquadratic filter equation [closed]
I am trying to calculate input impedance of a multiple feedback low pass filter. What I need is the symbolic expression as simple as possible so that later I fill in the values and get the impedance ...
0
votes
1answer
871 views
As ISA Practical - Resistors in Parallel [duplicate]
Possible Duplicate:
Current against the inverse of resistance graph, I = V/R +c
How would you set up a circuit with a fixed resistor in parallel with a variable one. We are told to measure ...
2
votes
1answer
363 views
Electrical flow in a simple parallel circuit
I'm having trouble understanding something in one of my text books:
Let’s have a look at the implications of each circuit configuration.
Figure 3.13 shows the Conventional representation of a ...
3
votes
1answer
90 views
buiding circuits from color superconductors
caveat: the sort of exotic matter engineering in here is currently beyond the reach of our technology, but, that having been said:
Has their been any research on building models of these sorts of ...
6
votes
2answers
686 views
Lots of little questions about radiation of LC circuits
I'm trying to get a more intuitive understanding of resonant inductive coupling. It's supposed be a more efficient way to transfer electrical energy wirelessly, because the coils are only coupled by ...
3
votes
2answers
531 views
Relating milliampere-hours to watt-hours for batteries
I've seen many batteries that are measured in milliampere hours (mAh), while others are measured in watt hours (wh). How can I convert them between each other so that I can actually compare them? It's ...
2
votes
1answer
147 views
What electric potential is found over individual resistors connected in series to an AC power supply?
Given a set of resistors connected in series to an AC power supply:
What formula governs the peak-to-peak voltage which will be measured when voltage is probed over individual resistors and sets of ...
0
votes
0answers
174 views
Equations that govern SPICE models and how to perform the same simulations in MATLAB [closed]
SPICE is a great tool, but I want to be able to write my own code in MATLAB such that I can get faster results.
To start with, I have a simple but specific requirement. Once I understand and can ...
2
votes
2answers
716 views
Voltage and Current in transformers
In transformers, the ratio of the voltages equals the ratio of the turns - so double the output coil's turns and the output voltage doubles. Then, in order to conserve energy, current halves.
This ...
2
votes
2answers
696 views
What is the potential difference between point X and point Y?
Here is the problem:
In the above figure I want help on finding the potential difference between X and Y.
It is getting quite confusing due to the battery in the middle. I found the current in both ...
7
votes
1answer
435 views
Can an arbitrary RLC-circuit network have non-minimum phase zeros?
I am working with certain input-output maps that can be thought of as large RLC-networks. I thought maybe this might be a place to get some thoughts/ideas/answers.
My basic question is, given some ...
2
votes
1answer
223 views
Circuit Simulation
I am making a circuit simulation program, and I am not sure how to simulate the behavior of Diodes.
Take this circuit:
...
2
votes
1answer
231 views
No Voltage in a Circuit but still a Current, How?
Hi I've done an experiment in physics using a basic circuit. Can anybody explain how come the data logging equipment I was using continued to register a current when there isn't a positvie voltage in ...
0
votes
1answer
2k views
Ohm's Law and Space-Charge Limited Current
I am trying to understand Space-Charge-Limited-Current (SCLC) and the resulting Mott-Gurney Law.
My main problem is conceptual; I don't get why SCLC doesn't produce Ohm's law (j $\propto$ V).
4
votes
5answers
3k views
What would be the effective resistance of the ladder of resistors having n steps
I'm a tutor. This is a high school level problem. In high school, every one have might have solved a problem of effective resistance of a ladder of resistors having infinite steps. Now the problem is ...
1
vote
0answers
209 views
Creating an ammeter? [closed]
Three resistances AB, BC, CD are joined in series and placed across the terminals of a galvanometer. The resistance of the galvanometer is 15 ohm and it gives full scale deflection for a current of 5 ...
0
votes
1answer
155 views
Waveforms for a given ideal inverters circuit
I have the following circuit. All the inverters are ideal CMOS.
I need to draw the waveforms for each point (A, B, D, E, Vo), given that waveform at input.
What I want to ask is if what I did so ...
2
votes
4answers
790 views
Calculating current used by individual resistor?
I just recently finished a test on Physics, and when receiving my scores back I missed a question. Here's what it was if I can remember it correctly:
Three resistors (10.0, 15.0, and 6.00 ohms) ...
3
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2answers
2k views
9
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1answer
770 views
Matrix solution of an equivalent resistance circuit problem
Start with a set of points $x_1, x_2, \ldots$ that are connected by wires with some resistance. Represent the resistance by a conductance matrix (conductance being one over the resistance), where ...
0
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3answers
663 views
Direction of Magnetic force from a current running through a coil of wire
What is the direction is the magnetic force vectors pointing from a coil of wire that has current running through it?
...
-1
votes
1answer
325 views
How does mass relate to resistance (Ohm's Law)
How can I relate mg to R?
Just to give you a scenario: If a free hanging weight was tied to a motor... I know the voltage (V) and current (I) so I can use V = IR to find R. What if I reduce the ...
2
votes
1answer
626 views
Current from induced emf
If the induced emf in a circuit is negative, and current from this emf is the emf over the resistance, what happens to the negative sign in the induced emf when solving for the current? Surely there's ...
6
votes
1answer
442 views
Why does breaking one bulb on a string of Christmas Lights cause all the rest to break in some lights?
If I break one bulb on a string of Christmas lights, or the filament goes out, then all of the rest seem to stop working. Why is this?
However, I've also seen the opposite happen in some newer ...
