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Author Topic: ALL PHYSICS DOUBTS - POST HERE !!  (Read 225621 times)

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1470 on: May 25, 2010, 07:37:22 pm »
Quote from: deadman786 on May 25, 2010, 07:28:32 pm

hahaha thanks!!!!!!!! U're a life saver. Just 1 final thing, this explains why a capacitor won't charge with AC cause it will prevent accumulation of charges right?? Meaning it will charge and discharge??? And to produce an induced EMF, is it necessary to use an alternating field (the one provided by AC)?? Since DC will not produce an alternating field and no induced EMF right????
my txt bk says dat capacitor will nt wrk wid dc n will wrk wid ac
<Cambridge IGCSE Physics- Tom DUncun   pg 196 :P :P :P :P lol>
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Offline 8T

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1471 on: May 25, 2010, 07:37:35 pm »
Quote from: ~VIN1094~ on May 25, 2010, 07:29:41 pm
See its a metal ball .. it doesnt hav a pole until another magnet 'sticks' to it .. S or N .. doesnt matter for the ball
Thanks 4 the effort .. I get it Now (:
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Offline igext

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1472 on: May 25, 2010, 07:37:58 pm »
can some one tell me what is the purpose of the core in a transformer?
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Offline Helium

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1473 on: May 25, 2010, 07:39:27 pm »
 
Question, can anyone solve and scan ,
or at least explain how to do it, (dont worry i'll understand)
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Offline igext

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1474 on: May 25, 2010, 07:40:56 pm »
Quote from: Helium on May 25, 2010, 07:39:27 pm

Question, can anyone solve and scan ,
or at least explain how to do it, (dont worry i'll understand)
the resultant of these 2 forces is actually the weight of the box or wht ever being lifted
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Offline the_grim_reaper

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1475 on: May 25, 2010, 07:41:16 pm »
Quote from: igext on May 25, 2010, 07:37:58 pm
can some one tell me what is the purpose of the core in a transformer?

It is there to prevent leaking of the alternating field which will produce a strong induced EMF, without it, not all of the alternating field (which should induce an alternating EMF) will reach the other wire so a weaker EMF will be induced.

Correct right??? Please correct me if I'm wrong....
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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1476 on: May 25, 2010, 07:42:06 pm »
Quote from: igext on May 25, 2010, 07:37:58 pm
can some one tell me what is the purpose of the core in a transformer?

the voltage induces in the core itself .. without it the transformer wouldnt work ..
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Offline igext

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1477 on: May 25, 2010, 07:42:13 pm »
Quote from: deadman786 on May 25, 2010, 07:41:16 pm
It is there to prevent leaking of the alternating field which will produce a strong induced EMF, without it, not all of the alternating field (which should induce an alternating EMF) will reach the other wire so a weaker EMF will be induced.

Correct right??? Please correct me if I'm wrong....
hmm not rlly clear
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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1478 on: May 25, 2010, 07:42:55 pm »
Quote from: Helium on May 25, 2010, 07:39:27 pm

Question, can anyone solve and scan ,
or at least explain how to do it, (dont worry i'll understand)

gimme some time ;)
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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1479 on: May 25, 2010, 07:43:22 pm »
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Offline Shazizzzle

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1480 on: May 25, 2010, 07:43:38 pm »
Quote from: igext on May 25, 2010, 07:37:58 pm
can some one tell me what is the purpose of the core in a transformer?

The core is mainly made of iron, A CONDUCTOR, and so, serves as the purpose of CONDUCTING or TRANSFERRING the current from the primary coil to the secondary. It helps with the electromagnetic induction. As a conductor, to allow and speed up the transfer of current process, and it itself is induced.

The core is also made of pieces which are joint via lamination, and not just one whole piece, to avoid building up of eddy current.
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Offline igext

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1481 on: May 25, 2010, 07:44:17 pm »
Quote from: ~VIN1094~ on May 25, 2010, 07:42:06 pm
the voltage induces in the core itself .. without it the transformer wouldnt work ..
my teacher said the current is directly induced in the 2ndry coil with out the help of the core
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Offline Adzel

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1482 on: May 25, 2010, 07:45:24 pm »
see attached...
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Offline the_grim_reaper

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1483 on: May 25, 2010, 07:45:46 pm »
Quote from: ~VIN1094~ on May 25, 2010, 07:34:58 pm
ok u said "a capacitor won't charge with AC cause it will prevent accumulation of charges right??" PERFECT!

 " Meaning it will charge and discharge"  i dont think it will charge on the first place because the to and fro is so fast tht the capacitor wont be able to have enough time to get charged .. ;)

" And to produce an induced EMF, is it necessary to use an alternating field (the one provided by AC)?? Since DC will not produce an alternating field and no induced EMF right????"   yup this is right .. do you know WHY ac is needed for induced pd ??

THanks!!! Ummm since only AC can produce an alternating magnetic field only that can produce an induced EMF?? Lenz's law says that the direction of the induced EMF should be to oppose the change causing it so the field by DC will not induce an EMF since it won't oppose the change causing it?? HAHAHAHAHAHAH LOL. I don't know :D.
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Offline 33oomar

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #1484 on: May 25, 2010, 07:48:29 pm »
Guys.. I need help in
question 39   may/june 2007 paper 1
Please help meeeeee :(
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