Current Flow

[rktpro]

The drift velocity of electrons is very small, approximately 1 mm/s. Then why light turns on instantly when switch is pressed? Is is due to the fact that electrons transfer energy to one another and thus conduct electricity without physically moving from one point to other?

[DrRocket]

The drift velocity of electrons is very small, approximately 1 mm/s. Then why light turns on instantly when switch is pressed? Is is due to the fact that electrons transfer energy to one another and thus conduct electricity without physically moving from one point to other?

 

 

The energy transferred in an electric comes from the electromagnetic field, not the kinetic energy of the electrons.

 

Now think about a long pipe narrow filled with pping-pong balls. Push on a ball at one end. Another ball pops out at the other end almost instantaneously, despite the fact that the individual balls move slowly and not very far.

[swansont]

The energy transferred in an electric comes from the electromagnetic field, not the kinetic energy of the electrons.

 

Now think about a long pipe narrow filled with pping-pong balls. Push on a ball at one end. Another ball pops out at the other end almost instantaneously, despite the fact that the individual balls move slowly and not very far.

 

And you can take this analogy one step further. If the pipe is big and has many ping-pong balls across its cross-section, even a slow motion of an individual ball can result in many balls coming out per unit time. Current comes from the large number of available charges, rather than the charges having a large velocity.

[rktpro]

The energy transferred in an electric comes from the electromagnetic field, not the kinetic energy of the electrons.

 

 

Electromagnet field or electric field?

[DrRocket]

Electromagnet field or electric field?

 

 

The electric field is one component of the electromagnetic field. Energy flow is described by the Poynting vector which is the cross product of the electric and magnetic components of the electromagnetic field.

[rktpro]

Dr. Rocket. Is there any relation between gravitational field and electromagnetic field? Like, If I throw a magnet through a circular loop what would be the acceleration of magnet? Equal to g or less than it?

[Dovada]

Is there any relation between gravitational field and electromagnetic field?

 

Yes there is a direct relationship, but science has not officially discovered it yet.

 

For example like particles like electrons, normally repel each other due to their electrical charge being identical polarity.

 

When you move these electrons their electrical charge effectively then becomes an electric current. The magnetic phase properties produced by the electric current flow is in-phase due to a common motive direction and the normally repulsive electrons then become electromagnetically attracted together.

 

This is the same condition as described under parallel conductors http://en.wikipedia.org/wiki/Amp%C3%A8re%27s_force_law

 

It is necessary to understand that all atomic structure is permanently in motion within the cosmos, a condition which can satisfy the Ampère's force law and because of this atomic matter can and does experience an electromagnetic attractive force. We normally refer to this as the gravitational effect.

Edited October 14, 2011 by Dovada

[Schrödinger's hat]

Dr. Rocket. Is there any relation between gravitational field and electromagnetic field? Like, If I throw a magnet through a circular loop what would be the acceleration of magnet? Equal to g or less than it?

 

Uhmm, the electromagnetic field does contribute to the stress-energy tensor. It will have a gravitational field different to a non-magnetic object, albeit very very very very slightly different.

 

I don't quite understand what you mean by circular loop in this context.

If the loop is conductive you get an induced current which will result in the magnet slowing. However, this is a purely electromagnetic phenomenon.

Even non-conductors will react to the EM-field very mildly.

 

I can confidantly say that at all but incredibly high energies the electromagnetic and gravitational effects will be independant.

For any experiment you can conceive of, you can consider the EM field and its interactions with charges separately from the gravitational field/spacetime curvature and interactions between masses separately. Then add the two sets of effects to get the right result.

For incredibly strong fields you might need to consider the energy-momentum they contain, but otherwise you could ignore them for the gravitational effects.

 

I do not know (and I do not know whether anyone knows) if there are coupling terms between the EM field and the gravitational field at higher energies. Or even if that makes any sense in terms of general relativity.

[Dovada]

If the loop is conductive you get an induced current which will result in the magnet slowing. However, this is a purely electromagnetic phenomenon.

 

I agree in that this is a purely electromagnetic phenomenon. If the loop is conductive the motion of the magnet will have some of its energy imparted to the ring and a back EMF from the ring will be subsequently imposed on the magnet.

 

Equal to g or less than it?

This depends only on the acceleration force you impart to the magnet and has nothing really to do with the earths gravitational field.

Edited October 14, 2011 by Dovada

[swansont]

Yes there is a direct relationship, but science has not officially discovered it yet.

 

…

 

It is necessary to understand that all atomic structure is permanently in motion within the cosmos, a condition which can satisfy the Ampère's force law and because of this atomic matter can and does experience an electromagnetic attractive force. We normally refer to this as the gravitational effect.

 

!

Moderator Note

STOP. Speculations being posted in response to mainstream physics is a violation of rule 10.

[rktpro]

This depends only on the acceleration force you impart to the magnet and has nothing really to do with the earths gravitational field.

 

The circular loop would, as far as I know, would get the same pole by inductance as the pole of magnet moving towards it and therefore it will repel and acceleration would be less.(I learned that myself when I couldn't get a reply here)

But you are saying about acceleration of magnet. Is acceleration of magnet responsible for the intensity or strength of pole induced?

[swansont]

The circular loop would, as far as I know, would get the same pole by inductance as the pole of magnet moving towards it and therefore it will repel and acceleration would be less.(I learned that myself when I couldn't get a reply here)

But you are saying about acceleration of magnet. Is acceleration of magnet responsible for the intensity or strength of pole induced?

 

It would be speed-dependent, since the induced potential depends on how fast the flux is changing. [math]V = - \frac{d\phi}{dt}[/math]

[DrRocket]

Dr. Rocket. Is there any relation between gravitational field and electromagnetic field? Like, If I throw a magnet through a circular loop what would be the acceleration of magnet? Equal to g or less than it?

 

In classical Newtonian/Maxwellian physics the two are completely independent, and that is a very good approximation except in extreme circumstances. In general relativity both mass and energy, including electromagnetic energy contribute to gravitation, but it takes a lot of energy to have much real effect.

 

If you throw a magnet through a ring, a lot depends on whether or not the ring is conductive. If the ring is conductive an eddy current will be set up in the ring that will create a magnetic field that opposes the motion of the magnet. This "magnetic damping" is often used in laboratory scales. If the ring is not conductive then nothing unusual will happen -- maybe you score a point depending on the rules of the game.

[Dovada]

!

Moderator Note

STOP. Speculations being posted in response to mainstream physics is a violation of rule 10.

 

My apologies swansont, I did not mean to break any of the forum rules.