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0answers
33 views

How does electric current continue to flow in a circuit despite there being zero potential difference?

Consider a conductor connected to a battery by conducting wires. When wires are connected then after a very small amount of time steady state is achieved and voltage across conductor becomes equal to ...
0
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1answer
89 views

Why can't free electron flow in water to conduct electricity?

This question is related to how batteries work. In a battery, the electrons can only flow in conductors, because they can't flow in the solution. my own thoughts on the matter: I believe it is ...
-1
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1answer
42 views

How electric current is defined in a metal wire?

How current is defined if in a metal wire both positive and negative charge exist? Isn't the total charge/time 0?
2
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2answers
54 views

Is it possible to become electrocuted even if using a Faraday suit on a high-voltage line?

I am a writer. I'm working on a novel (yes, fiction) but want to do my best to present a passage as accurately as possible. The crux of the question is whether or not someone using a Faraday suit ...
0
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1answer
203 views

Charge accumulation in wire

I came across a question about charge accumulation. It states that if a steady current flows in a wire composed of a copper and iron wire of same area (see fig), will the charge accumulate on the ...
0
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2answers
82 views

How does the current become homogeneous within a circuit?

I have two questions: In a given circuit with resistances of different values connected in parallel, there is a different build up of electrons when the power source is turned on. Then, how is the ...
1
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1answer
56 views

Creation of electric field inside a conductor

My book says that as soon as the two ends of a conducting wire touches the two terminals of a battery, it generates an electric field inside the conductor. Why?
1
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1answer
58 views

derivative of the electric field along the normal to the surface near the conductor

how to derive the formula approves the derivative of the electric field along the normal to the surface near the conductor is inversely proportional to the principal radii of curvature? $\frac{\...
1
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2answers
53 views

Does electric current create positive ions while flowing through a conductor?

As the conduction electrons are free to move randomly, i.e they are not restricted to a particular atom, then why don't these atoms get positive charge due to loss of these conduction electrons?
0
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3answers
190 views

Electric shielding skin depth

I read that lower the frequency,the deeper is the skin depth in conductor.If we are using piece of thin conductor,like aluminum foil for example to shield something from electric fields,it would ...
-1
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2answers
57 views

Some questions regarding electric properties of materials [closed]

I was reading Chapter 29 on Halliday-Resnick-Krane regarding this but couldn't understand these things. Suppose you have a conductor in an electric field. In normal conditions the field inside the ...
1
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4answers
379 views

Car hit by a lightning strike

In Griffiths' Introduction to Electrodynamics, at the Electrostatics chapter, in particular, in the conductors section, he says this after the stating that within an empty cavity surrounded by a ...
0
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2answers
392 views

What is drift speed in electricity and how is it related to the cross sectional area of the conductor?

In fluids dynamics, I learnt that as rate of flow is constant for an ideal fluid, Area(cross sectional area of the tube) x velocity is constant.I had a doubt whether the same relation exists between ...
0
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1answer
52 views

Mechanism of electricity in conductors

In mechanism of electricity in conductors my teacher said the free electrons collide with positive lattice and this positive lattice is oscillating about its mean position. Ok for producing current ...
0
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1answer
66 views

Capacitance due to accumulation of charge on the interface between resistors

It is well known that the continuity condition for current density necessitates that at a steady state: $$\frac{\rho}{\epsilon_0}=-\frac{E\cdot \nabla \sigma}{\sigma}$$ Where $\sigma$ is the ...
0
votes
2answers
73 views

What is the cause of opposite electric current direction of flow of current inside a battery?

My question is that why the direction of current inside a battery is different than that of outside battery?Can someone explain how current is even carried inside a battery because free electrons aren'...
1
vote
1answer
56 views

What's happening at a molecular level to the resistance when the temperature of salt water is increased?

What's happening to the electrical resistance at a molecular level when the temperature of a water with a bit of salt is increased? I noticed that the resistance decreases but in metals it is totally ...
0
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0answers
103 views

Kubo formula derivation

In the derivation of the Kubo formula for conductivty we write the total hamiltonian as $$H_{\text{tot}}=H_0+H_{\text{ext}}$$ where $$H_{\text{tot}}=H(A_0+A_{\text{ext}}),$$ $$H_0=H(A_0)$$ and $$H_{\...
0
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1answer
38 views

Is the speed at which electrons move through a conducting wire binary?

If a voltage differential causes electrons to move through a conducting wire, and no other forces are acting against them, will they always move at the highest possible speed through that material? ...
1
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2answers
117 views

There is no electric field in a metal if the current through the conductor remains constant.

In a chapter of superconductor, I found, "There is no electric field in a metal if the current through the conductor remains constant". My question is, "Why the electric field is zero in such case?". ...
1
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1answer
1k views

Can you conduct electricity through a banana peel?

While grabbing a banana for breakfast today I got zapped due to static electricity building up while I was moving on my chair, but the conductor I was grabbing was said banana. Is it possible to ...
15
votes
3answers
5k views

Tree vs lightning rod: why does one burn and the other not?

I have this simple question, but I cannot find the answer. I saw this video about a plane getting hit by lightning. In it, Captain Joe explains why people do not get electrocuted. This has a simple ...
0
votes
1answer
47 views

Point resistance

The resistance of a given object is expressed through: $$R=\rho\frac{l}{A}$$ I'm wondering if there is any quantity like resistance at a specific point. For example, $R$ for a copper wire with l=...
1
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3answers
188 views

Is it possible for a conductor to run out of free electrons?

For example, imagine I apply a high voltage to a piece of conductor (copper) and make the electrons jump out of it like a automotive spark plug. Can the copper after a prolonged period of time run out ...
0
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1answer
656 views

Dielectric Grease on Electrical Connections

The electrical connection between my truck and our RV trailer was intermittent. When I wiggled the connection the errant light would go on and off, so I bought some electrical grease and problem ...
36
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5answers
22k views

Speed of light vs speed of electricity

If I arranged an experiment where light raced electricity what would be the results? Let's say a red laser is fired at the same time a switch is closed that applies 110 volts to a 12 gauge loop of ...
1
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2answers
494 views

Does an electron physically flow? [duplicate]

In a DC current in a conductive wire, is it more accurate to think of one electron wiggling its way through a sea of electrons... or to think of one electron bumping into another, which bumps into ...
0
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1answer
146 views

What is electric current? [closed]

I have been reading a book about electricity which states that: electric current is not the movement of electrons but the "impulse generated when free electrons orderly "jump" from one atom to the ...
-1
votes
1answer
296 views

Physics of throwing a power cord into a swimming pool

I saw a few questions related to swimming pools so I figured out I may ask here. If one takes a power cord that's plugged into a wall socket on one end and throws the other end in a bath, it may kill ...
1
vote
1answer
66 views

Resistance Being Proportional to Length And Its Relation to Magnitude of Current

"Resistance of an electrical conductor is proportional to it length" The intuitive explanation I found in many articles was that the greater the length of the conductor, such as a wire, the greater ...
3
votes
2answers
319 views

Temperature distribution in a current carrying conductor

A rod of uniform cross section and composition is connected across a battery. Let the middle part of the rod(when divided into three equal parts) is heated uniformly. A book says that the temperature ...
5
votes
4answers
370 views

What do we mean when we say an electron collides with a molecule or atom?

When current flows through a conductor, it is said that the flowing electrons collide with the molecules or atoms of that conductor which causes resistance. The collision of electrons with molecules ...
2
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1answer
37 views

Electric charges

It is known that why we see a small bit of lightning or an electrostatic shock is when placing a negatively charged conductor to a neutral conductor, isn't it? My question is why do feel hurt or ...
56
votes
6answers
22k views

If water is not a good conductor, why are we advised to avoid water near electricity (no wet hands near circuits etc.)?

How can water be a medium to conduct current while its ionisation is so negligible that, in principle, no current should flow?
0
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3answers
504 views

Heating of an non-ohmic conductor

So I know that if you increase the voltage across a wire then the current will increase. But an increase in current leads to a increase in heat production though $P=I^2R$, but as the temperature ...
0
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3answers
207 views

Field due to internal Induced charge on a conductor to an external point?

A charge q is located at a distance r from the center of a conducting sphere with inner radius 2r. The charge induces charges on the inner surface of the sphere according to Gauss' law . The electric ...
3
votes
2answers
561 views

How is the speed of electricity determined?

Before I am told this is a duplicate, I'd like to be specific here. I have searched online for an answer regarding the speed of electricity in general and haven't found what I'm looking for. Even in ...
4
votes
2answers
317 views

Why do electrons follow the conductors shape?

I'm stuck thinking about this situation. I imagine that there are two oppositely charged objects at short distance $r$, put inside an insulator (Can I say air?). They generate a net elctric field, ...
1
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3answers
421 views

Does saline water lose conductivity over time?

When current is passed through a beaker of salt water, the ions move towards the terminals (based on their charge– e.g., sodium ions to the cathode and chlorine ions to the anode). Following this ...
1
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0answers
614 views

Tap water conductivity differences between AC and DC

Direct current is often used in electrolysis and because of the alternating nature of AC, it's not great for electrolysis. Tap water, however, conducts AC really well. But why is that? Why does ...
4
votes
4answers
639 views

Hollow conductor containing charge: why is internal field cancelled outside and why are the field oustide the cavity zero inside the cavity?

I've a doubt on the following situation. Consider a hollow conductor $A$ (of arbitrary shape) containing another conductor $B$ (again of arbitrary shape), with a positive charge $+q$. By the ...
1
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2answers
898 views

Is it safe for a man standing inside a Faraday cage to touch it from inside

Will a man get electrocuted if he touches a Faraday cage from inside when a high potential difference is developed between a Faraday cage and some other source? If yes then how a person wearing ...
11
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2answers
8k views

Where do all these electrons come from? [duplicate]

I'm a high school student and I'm fairly familiar with basic electronics, but I've always wondered one thing. So how generators make electricity from motion is the move a magnet around or through a ...
0
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1answer
212 views

Why are spheres supposed to become discharged?

Source of image: Fundamentals of Physics extended fifth edition by Halliday, Resnick and Walker. Concerned to First Paragraph. Why in the rejected scheme, Spheres are supposed to go neutral (or ...
0
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1answer
263 views

Conduction and Ionic Conduction

How the ionic conduction is different from normal conduction ? Does the electrons that leave atoms completely conduct in ionic conduction while in normal conduction the conduction takes place through ...
0
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0answers
30 views

How am I obtaining silicon with resistivity proportional to the number of conduction electrons?

The resistivity of silicon is given by $$\large\rho=\rho_0e^{\Large{{\frac{E_g}{2k_BT}}}}$$ and the number of conduction electrons in a semiconductor conduction band is $$\large n_{\text{...
3
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1answer
283 views

How do electrons move at an atomic level? [duplicate]

This was meant to be a sub question in the comments of my last question but I think it is big enough to have its own post. I know that electrons move because of the potential difference across the ...
-3
votes
1answer
312 views

How electricity works acutally?

I've been told that electricity is due to flow of charges(-ve charge=electron) that are provided by the battery. And no. of charges that leave battery at one end are equal to no. of charges that re-...
1
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1answer
122 views

How does the energy of a charge above a metal plate compare to two point charges?

Suppose you have the classic method of images problem. You have a point charge $q$ sitting a distance $d$ above grounded metal plate. You can then find the field as though there were 2 point charges ...
1
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1answer
83 views

How increased current carrying capacity / ampacity affects wire gauge size [closed]

In selecting a suitable wire size for manufacturing: If I have a material that has the same resistivity and density as Copper, but has a higher current carrying capacity / ampacity for the same ...