is lenz's law overly complicated for no reason?

[tdod]

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with lenz's law, they always talk about weird crap like "flux" and the "system undoing changes."

but when I do problems, it seems like a loop just enters a magnetic field, and a current is induced. nothing special.... the current is only induced when entering/exiting the B field, b/c when it is in the middle of the field both sides of the loop feel equally strong magnetic forces, so they cancel.

am i missing something?

 

[jrhuynh94]

Isn't flux simply the area of the loop contacted by the magnetic field hence moving a loop in and out of the field simply changes the flux?

 

[Cawolf]

Lenz's Law is actually a highly oversimplified application of the Maxwell-Ampere relation . . .

Flux is the integral of B.dA so it also includes a change in area of the loop.

It mainly describes how the induced current will flow in a direction that opposes the caused that created it - so you can intuitively determine the direction of current without doing calculations to find if your answer is negative or positive.

 

[Jason12]

with lenz's law, they always talk about weird crap like "flux" and the "system undoing changes."

but when I do problems, it seems like a loop just enters a magnetic field, and a current is induced. nothing special.... the current is only induced when entering/exiting the B field, b/c when it is in the middle of the field both sides of the loop feel equally strong magnetic forces, so they cancel.

am i missing something?

the whole concept behind lenz's law is based on lechatelier principle, that an electric current induced by a changing magnetic field will flow such that it will create its own magnetic field that opposes the magnetic field that created it

 

[TBRBiosadist]

Actually lenzs simplifies the complex topic of flux to something very similiar to le chats principle. Be happy it is as simple as it is.

 

[IslandStyle808]

with lenz's law, they always talk about weird crap like "flux" and the "system undoing changes."

but when I do problems, it seems like a loop just enters a magnetic field, and a current is induced. nothing special.... the current is only induced when entering/exiting the B field, b/c when it is in the middle of the field both sides of the loop feel equally strong magnetic forces, so they cancel.

am i missing something?

All the loop wants to do is reduce the flux and it does so by generating it own field (which counters the external magnetic field). The whole MCAT concept revolves around this idea.