All Questions
Tagged with electricity conductors
159
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Induced charge on conducting sphere sliced by a plane
We are given a conducting solid sphere, and it is cut by a plane as shown.
A charge $Q$ is given to the smaller part of the conductor, and it is required to find the induced charge on the surface of ...
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1
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Confusion about EM waves in a conductor, AC in wires, and skin effect
I am trying to get my head around these different points:
From Maxwell's equations we find that an electromagnetic wave in a conductor decays in amplitude with a characteristic length of about 1 cm in ...
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0
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34
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Maximum mean distance electrons can travel in ballistic conduction?
How far in mean distance can electrons reasonably travel via ballistic conduction according to the current model and what is the current mean or average distance or length record for ballistic ...
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3
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82
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About lightning and lightning conductor
Lightning not only strikes on a lightning conductor installed on the building... Lightning can strike anywhere on the surface roof of the building even though that building has installed a lightning ...
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If metals can’t sustain an electric field inside them (as their electrons move to cancel it out), how do they still conduct electricity? [duplicate]
I tried to understand by my own couldn't do so.
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3
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134
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Would this simple design function as an electromagnet?
I was thinking about electromagnets today and a thought popped up in my mind on what would be a very simple way to create an electromagnet.
Although I have not built and tested it, I am pretty sure ...
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Is Faraday's cage described in electrostatic 100% insulated?
I apologies if my wording is bad or it is duplicate.
I'm new to Electrostatics. During the topic of conductors & electric
field I was introduced to Electrostatic Equilibrium state in which
the ...
user380217
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180
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Does the physical shape of a current carrying conductor affect the shape of its magnetic field?
I am wondering if the physical shape of a current carrying conductor will have any effect on the shape of its magnetic field or is it that the magnetic field surrounding any current carrying conductor ...
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Is Net force per unit charge zero in a conductor in the presence of a magnetic field?
Let's assume there is a perfect conductor. This conductor starts moving with a constant velocity in the presence of an external electric field and magnetic field.
Generally an external magnetic field ...
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0
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Effect of pulsed electric field on the temperature of a conductor
I am wondering if my physical intuition regarding the following situation is correct.
Suppose we have an ordinary neutral conductor (say an ordinary piece of metal). We now turn on an electric field. ...
1
vote
1
answer
104
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If a downed powerline contacts the metal chassis of my car, can I touch any metal parts of my car while sitting inside of it?
consider the following situation. I parked my car underneath some high-voltage lines – let’s say 380 kV-lines. Suddenly, one of the lines breaks in the middle due to a storm and one end of the (still ...
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Since propagation of electricity takes time, does magnetic field (that iron filings organize around) build up gradually from one end toward the other?
In very long wires, such as hundreds of kilometers, when we flip a switch and turn on the electricity, does the magnetic field (that iron filings organize around) start to form in one direction and ...
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How does collision affect conductivity in metals? [duplicate]
Say we apply an AC electric field at some angular frequency $\omega$ onto a metal with a scattering time of $\tau$.
How does the relation between $\omega$ and $\tau$ affect the conductivity of the ...
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27
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Can you measure different currents at different contact points for a volume of material made of two different metals with different conductivities?
My question is about the variation of conductivity in a volume of material and its effect on measured current. A volume is comprised of two metals joined symmetrically in a cuboid shape as in the ...
2
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1
answer
557
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Do electrons really move on the conductor?
For my understanding:
Maxwell's equations combined with Poynting's theorem give us a model where electricity is energy carried along with the electromagnetic field (energy is stored in the field, not ...
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2
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Reasoning why the lightning shocks doesnt cause any shocks to a person inside car if the conditon is not fully electrostatic
I am just confirming here how the concept of electrostatic shielding helps in preventing lightining to be not getting into the car inside .
So we know car has a metal body outside , so first consider ...
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4
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Why is current density in a conductor of uniform cross sectional area constant at all points?
According to what I was taught, if current was dispersed “uniformly,” current density would remain constant.
So, in a conductor, the 'current density should be the same at all points.' But, given that ...
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Would a grounded copper heat sink located near a room's ceiling be an effective way to reduce a room's temperature?
I am thinking about a cheap but effective way to reduce the temperature of my bedroom in my apartment during hot summer nights. I live in an old apartment building and the air conditioner located in ...
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2
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EM energy flux and heat distribution in a cylindrical conductor
Consider a cylindrical conductor made of a single material (say, copper) with conductivity $\sigma$. Assume there is a current through the conductor and, to avoid complications, assume that the ...
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2
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1k
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Why can't we use a slip ring instead of a split ring in a dc motor?
I've been taught that in a dc electric motor a split ring is used to connect the two ends of the rotating coil to two carbon brushes so that
The wire does not get twisted and
The current passing ...
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4
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3
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302
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Why do we use wires/conductors to transport energy?
I am currently studying Maxwell equations and I learned that copper wires are essentially just wave guides for EM waves. Why do we not use an insulator to guide the wave and transport the energy which ...
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38
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How to measure water height thickness on infinitely flat surface with constant layer of water?
How would it be possible to measure layer of water on an infinitely flat surface, with every time different, but constant layer of water?
I'm trying to measure thickness from $1\rm\,\mu m$ to $5\rm\, ...
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4
answers
70
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Do you "lose" electricity when you course it through subpar conductors?
Imagine I had a basic circuit - say the classic 9V battery on one end, a couple of wires, and a little light bulb on the other.
Of course, in a real world example those wires would probably be ...
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2
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839
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What is the meaning of unit of electrical resistivity, ohm-meter?
In the unit of work done, $Nm$, $N $ stands for the force applied and $m$ stands for the length of displacement, by taking their product we get work done or $Nm$.
But in the case of electrical ...
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1
answer
86
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Does The electron get absorbed by nucleus in a conductor when they collide with the atoms [duplicate]
If my question is incorrect then please also mention the correct thing which happens to them.
2
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1
answer
908
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How does higher concentration leads to higher internal resistance in the cell?
Concise Physics mentions that:
Higher the concentration of the electrolyte greater is the internal
resistance(in a cell).
I think that higher the concentration of the electrolyte higher would be the ...
2
votes
2
answers
108
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How can net field inside a conductor be zero at every point? What if a charged particle is at that point?
The net electric field at any point inside a conductor which is not connected to an EMF source is zero and an external field is present. What is net electric field? It is the net field due to all the ...
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2
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342
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Does any time dilation take place within an electrical conductor when electricity is flowing through it?
I am curious to know if any time dilation takes place within an electrical conductor when electricity is flowing through it.
It is my understanding that an electrical current (electromagnetic waves) ...
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1
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72
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Running electrolysis on inside surface of a tube
I use electrolysis for rust removal and electroplating. I notice that when one of the electrodes is a closed tube or has other topological holes with a sufficiently large height:diameter ratio, the ...
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6
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2k
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Electric current definition
I'm trying to understand electric current. Some resources say that it is the flow of charge, and other resources say that it is the quantity of charge that passes through a cross-sectional area over a ...
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2
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Why exactly is the resistance of a conductor inversely proportional to the area of its cross-section? [duplicate]
Before I explain my query, I would like to clarify that I am a ninth-grader who got this question while studying the formula $R \propto \frac{1}{A}$ where $A$ is the area of cross-section.
I have ...
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0
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Is EM radiation released when metals, that have free electrons, are accelerated? [duplicate]
I have read that charged particles, when accelerated, emit Electromagnetic Radiation. This was the basis for rejection of the Rutherford's atomic model. But is this statement complete?
Metals have ...
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82
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Does making a conductor spiky increase its capacitance?
I'm thinking of the proofs for "charge accumulation at the points of a spiky conductor" e.g. https://www.feynmanlectures.caltech.edu/II_06.html 6-11
If charge accumulates at sharp edges, I'm ...
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43
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Confusion with Electrostatic Potential Difference
Suppose that you have a positively charged plate at a plane (xy-plane, for example). Therefore this plate exerts an electric field with a magnitude of σ/2ε₀. Due to this, there will be the same ...
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2
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758
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What force moves electrons through a conductor that is rotating in a magnetic field [closed]
Is it the magnetic force ( F= qv +B ) or the electromagnetic force (F= q(E+vxB) that acts on the electrons of a conductor that is moving in a magnetic field?
Thanks.
user232620
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Is carbonated water more conductive than salt water or baking soda-water mix?
Sorry for this entry level question, I'm an amateur, and I was wondering about alternative water mixtures for electrolysis.
My question is: Does carbonated water have better conductivity for ...
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172
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Does waterglass conduct electricity?
I'm wondering if waterglass (sodium silicate) either in solution and/or dry conducts electricity?
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1
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How is electric current possible if no electric field exists inside a conductor?
How is electric current possible if no electric field exists inside a conductor?
Since no electric field exists inside a conductor. How is electric current possible as $$v_d=\frac{(eE)t}{2m},\;\;{E=0}...
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1
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67
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At what speed does a magnetic field form from the flow of current?
When an electrical current flows through a conductor and produces a magnetic field, does the magnetic field in the conductor form at the drift speed of the electrons in its structure or the velocity ...
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1
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690
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Does the shape of a wire affect the electric current in it in any way?
Say we have a straight wire connected across two terminals carrying electricity between them. If everything is kept the same (voltage across the two terminals, resistance of the wire, etc.) will there ...
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4
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If an electron is repelled by another electron how is it that we get an electric current?
As we know that an electric current is a flow of electric charge in a circuit, and in electric circuits, the charge carriers are often electrons moving through a wire.
Now, since we know that like ...
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1
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62
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GENERATION OF CURRENT DUE TO ELECTRON FLOW
Why do flow of electrons generate current? whenever an electrons flows through a wire it generates electricity why does it actually happen?
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When you introduce excess charge into an insulator the charge stays still. Why is this?
When you add charge to an insulator the electrons stay in the same place whereas in a conductor they spread apart. Why is this? What force is making the excess charge stay in one place in an insulator?...
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Understanding conductivity at nanoscale and validity of Ohm's law
Nanoparticles such as gold and silver are becoming more and more used to print circuit or enhance electrical properties of another material. But I have not been able to find sources that clarify how ...
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27
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6
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Why do metals have free electrons?
Throughout my highschool classes, I have been made to learn that metals have free electrons that's why they are able to conduct electricity.. But I never understood why. Is that related to metallic ...
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3
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690
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Why are non-metallic elements with partially filled valence bands not conductors?
Throughout this whole question, I will be referring solely to single element solids. According to band theory, ns and np bands are close enough in energy to overlap and create one band with 8N states ...
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3
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233
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What do $\ell$ and $A$ precisely mean in the formula for electrical resistance?
The formula for resistance is
$$R=\rho\frac{\ell}{A}$$
Generally in most of the textbooks it simply written that $\ell$ is the length of the conductor and $A$ is it’s cross-sectional area. But my ...
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4
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3k
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In metals, the conductivity decreases with increasing temperature?
I am currently studying Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light, 7th edition, by Max Born and Emil Wolf. Chapter 1.1.2 Material equations ...
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93
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Does the electron in wire too move because of voltage difference?
When we talk about electricity through a circuit because of a battery it is said that the electrons from negative terminal travel to positive terminal of the battery.
I can't help but imagine about ...
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What causes the charges in conductor to move towards lower potential terminal of cell [duplicate]
Whenever a conductor is connected to a cell,what causes the conventional positivecharges inside it to move towards the lower potential level of cell..
My question is whether the charges experience a ...
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