Lenz's law - need clarification

[Werg22]

I only understand Len'z law for a current induced in a single loop... however I don't for in a coil... What does the relative poisition of the manetic poles of the magnet and the coil respectively has to do with the direction of the current?

 

[OlderDan]

I only understand Len'z law for a current induced in a single loop... however I don't for in a coil... What does the relative poisition of the manetic poles of the magnet and the coil respectively has to do with the direction of the current?

A coil is just multipe loops. If you understand what happens for a single loop, it happens N times as much for a coil of N turns. The direction of the current in each loop of the coil is the same as for a single loop. The induced emf is additive, so the total voltage is N times the voltage of a single loop. If the only resistance is external to the wire, the current will also be N times the current for a single loop.

 

[kyle8921]

Lenz's law states that the direction of an induced current in a conductor will always be such as to oppose the change that caused it. This means that when a magnetic field is applied to a conductor, the resulting current will create its own magnetic field that will oppose the original field.

In the case of a single loop, the direction of the induced current is determined by the right-hand rule, where the direction of the current is perpendicular to both the magnetic field and the direction of motion.

In a coil, the same principle applies, but it becomes more complex due to the multiple loops and changing magnetic field. The relative position of the magnetic poles of the magnet and the coil affects the direction of the induced current because it determines the direction and strength of the changing magnetic field.

For example, if the north pole of a magnet is approaching the coil, the changing magnetic field will induce a current in the coil in a direction that creates a magnetic field that opposes the approaching magnet. This is known as a back EMF (electromotive force) and is responsible for the resistance felt when trying to move a magnet through a coil.

On the other hand, if the north pole of a magnet is moving away from the coil, the induced current will be in the opposite direction, creating a magnetic field that will attract the magnet back towards the coil.

The relative position of the magnetic poles and the coil is crucial in determining the direction of the induced current, as it ultimately affects the strength and direction of the resulting magnetic field. I hope this clarifies Lenz's law for you.