Why does electromagnetic induction occur

[tor2006]

Greeting

I know the field of electromagnetism is not yet fully clarified but I wonder if there is an idea,theory Why does electromagnetic induction occur only when the conductor cuts the magnetic field lines.

 

[Orodruin]

I know the field of electromagnetism is not yet fully clarified

Classical electromagnetism is perfectly well understood in terms of Maxwell's equations. These are over 150 years old.

Why does electromagnetic induction occur only when the conductor cuts the magnetic field lines.

The magnetic force on a charge depends on its sign, velocity, and the magnetic field it moves through. The force on an individual charge will be perpendicular to both the magnetic field and the direction of motion of the conductor. In order for there to be a driving force in the conductor's direction, both the velocity and the magnetic field must have components perpendicular to the conductor's direction and cannot be parallel. As a result, the conductor will need to cut the magnetic field lines to produce a driving emf.

 

[NascentOxygen]

Why does electromagnetic induction occur only when the conductor cuts the magnetic field lines.

Using your figure as an example, where would the electrical energy come from if there were found to be induced current and voltage in even the stationary case?

 

[adaliadella]

Greeting

I know the field of electromagnetism is not yet fully clarified but I wonder if there is an idea,theory Why does electromagnetic induction occur only when the conductor cuts the magnetic field lines. View attachment 212528

It occurs whenever a magnetic field and an electric conductor move relative to one another so the conductor crosses lines of force in the magnetic field. The current produced by electromagnetic induction is greater when the magnet or coil moves faster, the coil has more turns, or the magnet is stronger.

 

[tech99]

Greeting

I know the field of electromagnetism is not yet fully clarified but I wonder if there is an idea,theory Why does electromagnetic induction occur only when the conductor cuts the magnetic field lines. View attachment 212528

People have said what happens but not why.
It is an interesting question, because stationary electrons are not attracted by a magnet.
But Maxwell says that a changing magnetic field creates an electric field. This creates an EMF across the ends of the wire, and so moves electrons which form the current.
It does this because it does this!

 

[cnh1995]

The current produced by electromagnetic induction is greater when the magnet or coil moves faster, the coil has more turns, or the magnet is stronger.

Usually I am not pedantic, but EM induction induces a voltage (emf precisely) in the conductor. So it's the voltage that is greater when, as you said, the magnet or coil moves faster, the coil has more turns, or the magnet is stronger (irrespective of the circuit resistance).

Current simply depends on the impedance of the circuit.

 

[cabraham]

Usually I am not pedantic, but EM induction induces a voltage (emf precisely) in the conductor. So it's the voltage that is greater when, as you said, the magnet or coil moves faster, the coil has more turns, or the magnet is stronger (irrespective of the circuit resistance).

Current simply depends on the impedance of the circuit.

Splitting hairs. When a time varying magnetic field is present, current & voltage are both induced. Regarding impedance of the circuit, we must include the inductance of the loop. If the inductive reactance exceeds load impedance, the load current & voltage remain near constant despite speed increasing.
Bicycle generators use this principle. Generator wound so that stator inductance is large. As pedal speed increases, headlight gets brighter. But frequency increases with speed, & stator reactance increases. Once stator reactance Xs, exceeds loiad resistance Rl, increases in pedal speed have little effect on headlight brightness. Generator is in constant current mode. Increasing speed produces increased frequency, which increases voltage dropped across Xs, resulting in c onstant current & voltage in headlight.

Usually I am not pedantic, but EM induction induces a voltage (emf precisely) in the conductor. So it's the voltage that is greater when, as you said, the magnet or coil moves faster, the coil has more turns, or the magnet is stronger (irrespective of the circuit resistance).

Current simply depends on the impedance of the circuit.