Solenoid Q (2 Viewers)

[t-i-m-m-y]

okay okay.. this seems like a bit of a controversy.. is that the word?... personally this question took a bit of thinking for me

Personally I wrote something along the lines of what Mathematician said.. both solenoids will move to the left... yet in slightly different manners.. the second one (circuit completed) will act as an electromagnet, similar to a bar magnet.. by lenz's law it will oppose the motion of the magnet.. repulsion that bits simple...

i think personally that the second one will still move slightly to the left.. and i wrote though as not as significantly.. as a current is indeed induced.. but there is no external circuit which it can flow thru.. thus the force is less... but there is still a slight movement, though not as significant

thats my 2 cents worth.. correct me if i'm wrong

 

[Ragerunner]

I said due to faradays law the rate at which the magnetic flux is cut is proportional to the size of the emf. and said that when a magnet is pushed in an emf will be produced

then i stated lenz law and say an opposing pole to oppose the N side of the magnet will be induced into the solenoid causing repulsion and pushing the solenoid a bit so it swings..

That correct?

 

[walla]

Eddy currents in the first coil are so insignificant its not funny, because the coils have almost no width

 

[dnt stop runnin]

im with "walla"............walla man, eddy currents have nothing to do with the question.......all they wanna know is what the difference in both is......which i think is that the first one, nothing will happen coz even if current is induced, there is no complete circuit.....however, in the second, a circuit is complete and it opposes the motion, therefore it will swing.....im not sure if thats right but im pretty sure eddy currents are irrelevant. wat u rekon??

 

[+:: $i[Q]u3 ::+]

ditto dnt stop runnin. sheesh.. if currents were induced in both so they both moved, why would they have the 'compare' bit?

 

[t-i-m-m-y]

Originally posted by +:: $i[Q]u3 ::+
ditto dnt stop runnin. sheesh.. if currents were induced in both so they both moved, why would they have the 'compare' bit?

btw....compare i think means both similarities and differences

*checks BOS syllabus glossary

 

[dnt stop runnin]

so am i right or wrong?? im just guessing

 

[ND]

Well it could still say compare if they were eddy currents, but i agree with sique, mikehunt etc.

 

[ghoolz]

I wrote that there will be eddy currents craeted by the application of Lenz's Law and that this will create a magnetic field apposing the direction of the motion of the magnet. This would cause the magnet to move only slightly on the pendulum, but still move.

The difference being that the second has a complete circuit and therefore there will be the flow of electrons.

I think it went something like that... alitlle more strung out i think and rushed.

 

[walla]

clearly they didn't intend for you to talk about eddy currents

 

[Bannanafish]

i only wrote about eddy currents cause i thought of it, i know it doesn't affect jack shit

 

[dnt stop runnin]

where everyone is getting eddy currents from i dnt understand......im getting scared now man

 

[Skywalker]

Both coils experience charge separation due to the changing magnetic field in the conductor. But to have current flow and the motor effect, you need a complete circuit hence the solenoid in Inv1 doesn't move at all. Which I think SiQue and walla have already mentioned several times...

 

[+:: $i[Q]u3 ::+]

thank you skywalker =)

 

[Dangar]

I said that eddy currents would be induced in the first coil but they would be so insignificant that it would not move. With the second one I said it would move because the changing magnetic flux blah blah blah... repulsive force... but then i also added that once the magnet was stopped the pendulum motion would eventually slow until it was still as there would no longer be any changing magnetic flux.
Smart?? please say yes..

 

[dnt stop runnin]

finally skywalker agrees with us........as for dangar, u should still get most of the marks for it......im just not sure about this eddy current stuff....coz eddy currents are only induced in ferromagnetic materials.....so im not sure...and u probably had to speak about th circuit not being completed

 

[worlds greatest]

did u guys talk about when it comes back? i think we were meant to, coz it was a trick
like "investigation 2" first it swings left
but when comes back (gravity) u get more relative motion again
u know what i mean
so its like.. repeated

also eddy currents: no, because there isnt enough space to go round. it only happens in mass metal, or is only significant enough
i think they didnt expect us to say it

 

[Mr.Moonlight]

I bombed it man, like what is a solenoid man, totally no idea of wat to answer

 

[~TeLEpAtHeTiC~]

lol i hav no idea where eddy currents are coming from either
essentially its just the relative motion inducing current in BOTH solenoids. however its only the SECOND solenoid that moves becuase the currents within the solenoid are flowing which induces the magnetic field to oppose the magnet
remeber that the current has to be moving to induce a magnetic field and so in the 2nd soleniod this is possible becuase of the complete circiut
in the 1st solenoid wether current is induced or not isn't significant becuase even if it is, it has no where ot go..so there is no movement..and so no magnetic field to oppse the magnet

hence 2nd soleniod moves in a force of repulsion and begins pendulum motion
1st solenoid doesnt move

 

[walla]

that's right except that you would need to say an emf was induced in the first, not a current. a current by definition moves so "a current with nowhere to go" is not a current.