The electric-circuits tag has no wiki summary.
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Does a current carrying wire produce electric field outside?
In the modern texts of electromagnetism in the presence of stationary currents the electric field is assumed conservative $\nabla \times E =0 $. Using this we get $E_{||}^{out}=E_{||}^{in}$ which ...
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Electromotive Force Definition for Induced Current
If in DC , Emf is the work done to carry a unit positive charge from -ve to +ve terminal .
What is induced EMF then , in a similar sense ? To carry a unit charge around a loop once along a fixed ...
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Is this series or parallel? [closed]
How do you find I? and please explain which resistors are in parallel and which are in series? ("M" and ">" are resistors)
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The heat dissipated in the resistance in a C-R circuit [closed]
If an uncharged capacitor (of capacitance $C$) is charged by connecting it with an ideal battery and a resistance R (The capacitor and resistor are in series combination ), then the heat generated in ...
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1answer
215 views
Frequency Response RLC circuit - Current against Frequency graph - Symmetry?
I understand that in a Frequency Response experiment dealing with an RLC circuit, the graph of Current against Frequency is supposed to be symmetrical about the resonant frequency theoretically.
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Alternating Current Circuits? [closed]
A 10.0 $\Omega$ resistor, a 12.0 µF capacitor, and a 17.0-mH inductor are connected in At what frequency is the current a maximum?
at resonant frequency the current is max:
$X_L = X_C $
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Why does a capacitor discharge?
Suppose a charged capacitor (parallel plates), the negative and positive charges on two plates attract each other. Which force cause the negative charge carriers (electrons) move through the circuit ...
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1answer
69 views
Can someone explain this intuitively please?
In a static situation we defined voltage as energy/unit charge, or j/c. As the distance between the charged particles increased, the voltage decreased. Now why do we not apply this in a simple DC ...
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Transfer functions of active filters
I've been looking for some straightforward method or trick to obtain the transfer functions of active filters (like the Sallen-Key filter, the butterworth or Cauer topology etc...) since KCL or KVL ...
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2answers
79 views
Out of phase voltage current source and resulting power
Examining the following graph, I am trying to understand the power plot. The power appears to take on a negative value when the current changes direction or the voltage changes polarity. Negative ...
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1answer
127 views
Path of an electron through an electric circuit
When a potential difference is applied across a conductor, and if an electron moves from the negative terminal of the battery and reaches the positive terminal, then I want to know if the electron ...
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3answers
174 views
How exactly does a resistance reduce current?
I've heard that resistors are used to decrease current to a particular appliance, such as in the regulator of a fan. However, I've also heard that the total current in a circuit is always the same- in ...
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1answer
85 views
Full wave rectification [duplicate]
In the construction of a full wave rectifier, why is there central tapping in the secondary winding of the power transformer? What's the pure reason behind it? If there was no central tapping, what ...
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half wave rectification [closed]
A.C of frequency 50 Hz was passed through a diode. The electricity thus obtained was used
to glow an led. Is there any peculiarity in the light from the LED? (1)
(b) If the glowing LED is whirled ...
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2answers
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Electronic filter
Can you explain, please, step-by-step how Electronic filter does work?
For example, high pass filter. I know It's a trivial things, but I can't get it completely. Don't bring me formula and etc... ...
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1answer
106 views
Am I properly identifying the resistor terminal voltage?
The frequency applied to a circuit of voltage 120 V with a real coil and a resistor has a value of 50 Hz. The resistance of the resistor is 10 $\Omega$. The voltage at the resistor terminals ...
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What is the value of the equivalent resistance? [closed]
Can anyone tell me the value of the equivalent resistance for resistors R7, R8 and R9 in the following image?
Circuit -> { http://www.mediafire.com/view/?ktct310wyvezf2x# }
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Why the CFL light bulb flashes even if there is a power cut?
Today when there was a power cut I saw that the CFL light bulbs were flashing time to time at regular interval. I was amazed as there was no source of power to the CFL bulbs even they were flashing as ...
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6answers
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Parallel circuits - Overall resistance decreases with additional resistor [closed]
Let's say that there is a parallel circuit with two identical resistors in parallel with each other. If a third resistor, identical to the other two, is added in parallel with the first two, the ...
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Round bulb and Long bulb in Series Circuit
If you have a series circuit with a battery, one round bulb (with thicker filament), and one long bulb (with thinner filament), the round bulb does not light up and only the long bulb lights up.
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Capacitor circuits with light bulb
Let's say we have a normal circuit with a light bulb, with wires and a battery.
When one places a capacitor in this circuit, how is the light bulb able to light up, even when the capacitor prevents ...
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1answer
340 views
What is the role of center-tapping in a full wave rectifier?
Note: I have already tried googling. Although similar questions have been asked on different forums, I couldn't find a detailed explanation, which I could really understand.
Circuit diagram ...
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1answer
567 views
Relationship between resistance and voltage drop
In a series or parallel circuit, if two bulbs have the same resistance, do they have the same voltage drops? The problem I am asking about is below. Do A, B, and C have the same voltage drops since ...
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1answer
104 views
a metal bar on a pair of conducting rails that carries a current
This is a homework question, and I solved it already, but something bugs me. So the problem is stated as following:
A metal bar of mass M sits on a pair of long horizontal conducting rails separated ...
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1answer
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Cable TV version of infinite ladder network [closed]
This is a problem in a college physics textbook, and its bugging me that I can't get it.
The figure shows a circuit model for the transmission of an electrical signal, such as cable TV, to a large ...
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1answer
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Weird circuitry problem [closed]
I should note that I am asking these questions on behalf of a friend who claims to be too busy. Anyway here is a circuitry problem:
Why is C the correct answer?
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Why is there a potential difference?
The question then asks for the potential difference between $X$ and $Y$, which is claimed to be $3.6\text{ volts}%$.
Why would there be a potential difference in this case? If I connect a lightbulb ...
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3answers
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kirchhoff's law.Simple question [closed]
So far I calculated total resistance and it is 4.66 ohms and there is 12 volt voltage across them, what is the best way or HOW to calculate current for each resistor ?
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AC Circuit Theory Maximum Power Transfer
I am currently hitting a barrier with regards to the basics of this question.
A 50HZ supply is connected to various given impedance's, calculate the maximum power transfer.
Maximum power transfer I ...
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2answers
801 views
Ohmic and Non-Ohmic devices
Why do some conductors follow Ohm's law and some do not? Isn't there any universal law that can explain the flow of current?
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Why does the current stay the same in a circuit?
I was informed that in a circuit, the current will stay the same, and this is why the lightbulbs will light up (because in order for the current to stay the same, the drift speed of the electrons need ...
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2answers
262 views
Why are AC quantities represented by sine waves always?
Usually we use a sinusoidal wave form to represent a alternating quantity. Why not a cosinusoidal wave or a ramp wave form?
In sine wave forms we can indicate the maximum and minimum amplitude and ...
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1answer
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Inductively coupled DC circuit
The circuit under consideration has two inductively coupled loops, one with a DC battery, inductor, and resistor in series. The other loop has two inductors, one inductively coupled to the first, the ...
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368 views
How to find the equivalent resistance for the following circuit? [closed]
How do you find the equivalent resistance for the above circuit, if current is entering via A and leaving via C? Can it be done by treating it like a wheatstone bridge?
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1answer
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Why does the presence of a battery change whether a circuit is in parallel or series?
If I take a closed circuit with two capacitors and a voltage difference, the circuit is apparently in parallel, but if I introduce a battery, the circuit is in series. Why does the presence of the ...
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Why and how does symmetry work in circuits?
Why symmetry work in circuits? In my book there is no mention explanation as such for symmetry arguments and circuits. But there are circuits that are very difficult to solve without symmetry. Also I ...
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Under what condition charges do not flow in closed circuit?
I wanted to ask under what conditions will charges not flow in a closed circuit. Or when is current through the circuit zero even when an EMF is applied?
Like in the case of potentiometer, we say that ...
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243 views
Flow of electrons in a circuit
When the electrons flow in a circuit, so are those the electrons from the battery or are those the electrons of conductor like copper wire, etc..which are flowing in the circuit?
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Positive test charge
Protons have positive charge on them. Protons aren't mobile. So how can a positive test charge move from the negative terminal of a cell to the positive terminal and gain electric potential energy? ...
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What are the statuses of Silicene and Graphene for real world circuit production?
A lot of hype is out there about both of them (especially the latter) and I was wondering if there is more concrete information about them other than the news IBM posted on a circuit 2 years ago and ...
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Are there general circuits that differentiate/integrate empirically?
Is it possible to construct simple circuits, that given a time-varying input, produce an output that represents the derivative or integral of the input with respect to time?
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How are current and voltage out of phase in capacitive circuit? [duplicate]
Possible Duplicate:
Physical explanation for capacitive circuit
We say that in capacitive circuit, the voltage and current are out of phase. Current is 90 (degrees) ahead of voltage. What ...
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What is the current through the lamp?
We have the following circuit:
A neon lamp and a inductor are connected in parallel to a battery of 1.5 $V$. The inductor has a 1000 loops, a length of $5.0 cm$, an area of $12cm^2$ and a ...
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1answer
192 views
Explanation of the Graetz circuit
My knowledge of circuits is pretty rudimentary and I've never really understood circuits, so I'm having trouble with the concept of Graetz circuits:
When you register the voltage on the resistor R ...
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Explanation of NMOS processes
So, gate (poly-si + $SiO_2$) and $p^{-}$ silicon operate as capacitator.
But how are voltages and charges are applied? In order for inversion to occur, there should be charges formed in poly-Si, ...
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1answer
569 views
Capacitor charging and discharging
I have a conceptual question.
The circuit is shown below. Let us assume that the capacitor shown in the figure is of 2.2 micro-farads having rated level of 5 volts and we decide to charge it up to 2 ...
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Physics understanding of MOSFET and CMOS [closed]
CAn anyone provide me some clear links or explanation regarding physics understanding of MOSFET and CMOS? I know CS logic understanding - but I want to know how MOSFET and CMOS are created, and how ...
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1answer
146 views
Physical explanation for capacitive circuit
In capacitive circuit, the voltage and current are out of phase. the current leads the voltage by 90 degrees. this can be explained by these two equations:
$$V = V_{\max} \sin \omega t$$
$$I = ...
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1answer
388 views
Effective resistance of inductor
In a lab experiment, we connected a simple circuit: an AC voltage source, connected (in series) to a variable resistor and an inductor. We measured the current in the circuit, and the voltage that ...
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How do I solve the current of this resistor using Maxwell's Current Theorem?
I've been trying to solve this using the method the prof. taught us, and I happen to know the answer but I can't reach it no matter how many times I've tried. The circuit in question is below:
I am ...
