Questions tagged [faradays-law]
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Why are induction motor cores laminated to prevent eddy currents?
The permeable iron alloy cores of induction motor rotors are formed from thin laminated sheets, designed to prevent eddy current flow and thus "reduce losses", but isn't the whole point of ...
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Faraday’s Law and voltage balance
Does anyone know how to use Faraday’s Law and voltage balance to explain this equation?
I don't understand where jw comes from.
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Analysing the behaviour of inductor in the circuit
Suppose we have an L circuit with DC power supply of emf \$\mathscr{E}\$
simulate this circuit – Schematic created using CircuitLab
By KVL,
\$\mathscr{E}=L\frac{dI}{dt}\$.
This suggests that \$\...
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How to find the points between which EMF is induced in a loop with resistors?
I recently came across a problem on Faraday's law, which had multiple resistors. The circuit looked something like this, with the loop rotating clockwise.
Personally, I felt that there would be three ...
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Does the direction of coil winding impact the direction of induced voltage?
I have taken and modified a bit the following image from a similar question, where it was explained that the direction of the coil winding does not impact the direction of the current: Does coil ...
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Induced voltage in loop around wire in home AC circuit
I have an electric patio heater that has no indication of whether it's on or off. I want to wrap a loop of wire around its power cord, the goal being to induce a current that can power an LED to tell ...
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How can the induced voltage be proportional to the frequency?
According to Faraday's Law, in coupled inductors, the magnitude of the induced voltage at the secondary coil is proportional to primary power source's frequency (V2 = w x I1 x M).
On the other hand, ...
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What is the EMF induced between two points in a closed wire loop?
Farday's law says if I change the magnetic flux through a closed loop an emf would appear.
Between what two points is the EMF calculated?
Let's say that my calculations give me an E=−dΦdt=10V.
What ...
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Constant Voltage Applied to Inductor
I'm seeking clarity on understanding what happens when a constant voltage is applied to an inductor. I gave this explanation in another thread and it was regarded as wholly misguided in the following ...
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What is the current induced in a wire connected to an ideal transformer using Faraday's law?
Imagine an ideal transformer interfacing an ideal current source with a ramp function \$i_1(t)=a t\$ connected to the primary winding and a resistor \$R\$ connected to the second winding. We want to ...
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Why does analysis indicate that ground lifts do not fix ground loops?
Note: "Ground loop" in this question refers to a ground loop caused by linked magnetic fields. (Sometimes ground loop refers to slightly different scenarios.)
Recently I've been looking into ...
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Waveform of induced EMF in a basic AC generator
Consider the following simple generator. A bar permanent magnet is rotating at a constant angular speed by some external means. Two coils of wire are placed in the same plane as the axis of the bar ...
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Should the magnetic field outside a conductor be considered?
I've simulated a circular disc where a magnetic field is moving out of the page. The arrows in the picture represents the direction of its current density.
I'm wondering, will the induced current ...
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Effect on current due to relative motion of load in homopolar generator
Description of figure -
A homopolar generator in which disc is rotating with constant angular frequency with respect to ground frame and a uniform steady magnetic field is present perpendicular to ...
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Electromagnetic farady's law direction
I have a question about direction of vectoral line integral in formula of electric potential and electric field.
In electrostatic I assumed \$B\$ is positive potential and \$A\$ is negative potential ...
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Sinusoidally squeezing a capacitor
Assuming no load, how does continuously changing the distance between the plates of a capacitor (in a sinusoidal fashion for simplicity) affect the output voltage? Does electromagnetic induction come ...
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Finding EMF from the given graphs
Here are the graphs of flux vs angle and EMF vs angle.
From it, I have to derive the following relation (expected answer) between EMF -Ui and change in flux with respect to time.
My approach:
I find ...
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What will be the graph of flux of coil 2?
In the following picture current is flowing through coil 1. Let's assume that current is increasing linearly in coil 1. Then emf induced in 2nd coil be will constant and having some negative value. ...
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Possible contradiction between Ohm's Law, KCL, KVL and Faraday's Law of Induction?
Let's say, we have a loop of wire of length \$L>0\$. Let's say, hypothetically, it is a loop of non-ideal wire. That means that the wire has a resistance per unit length \$ρ>0\$. Let's further ...
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Steel cooker is not a Faraday cage? [closed]
I read that steel/iron/metal/conducting cages, with gaps less than the wavelength of electro magnetic waves, shield whatever is inside from that radiation. But when I put my mobile inside a cooker and ...
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Maxwells Equation in Time varying field
The Maxwells Equation giving the value of Magnetic field (B) for stationary and moving coils are having different variables. How is the third equation possible with such 2 cases?
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If the self-induced EMF in an inductor is 180° out of phase with source voltage, shouldn't they cancel out and net voltage should become zero?
I know that inductor opposes the change in magnetic flux linked with it. In case of an ac sinusoidal voltage applied across a pure inductor, the emf induced across the inductor is equal and opposite ...
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Why is lenz law not applied in this crcuit analysis
So in this circuit, initially the current and voltage is 0. At t = 0 the voltage snaps to V.
Now my analysis is:
According to Lenz Law the voltage developed will ...
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How do we reduce or nullify the back current from the wheel motors of the modern electric vehicles?
As expected, this EMF opposes the voltage of the source that created it; that
is, the motor becomes a generator as soon as it is turned on, and the
opposing (or counter, or back) EMF will increase ...
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Confusion between Faraday's law and Kirchoff's circuit law
Consider a voltage source V connected to a coil. By Faraday's Law e=-(dƛ/dt). I don't understand the direction of the induced voltage e making v=-e
However, if we treat the coil as a circuit element ...
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Faraday cage and static electric field
Can anyone explain - what is the difference between static and varying electro-magnetic fields?
I know the definition for what is static electric field. It does not change with time (0Hz frequency.) ...
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A question about Faraday’s law of induction for a closed path
As far as I understand, Faraday’s law states that a varying magnetic field through a closed path creates an E-field along the closed path. And the integral of this field we call electric potential or ...
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