Working with magnetism, solenoid

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
7 replies · 3K views
Sox281212
Messages
9
Reaction score
0

Homework Statement


A bar magnet is held stationary (with respect to the loop of wire) at the centre of the loop with the North pole sticking out one end and the South pole sticking out the other. What happens to the size of any EMF induced in the loop once the magnet has been replaced by a magnet of twice the strength (i.e. you do the same thing, hold a stronger magnet stationary in the same position)? Explain your answer, with reference to Faraday's Law

Homework Equations


Faradays Law

The Attempt at a Solution


Ok so this is what I've gathered from TRYING to research online (i literally learned nothing in class)

When the current is running through the solenoid in one direction, and the north part of the magnet is inserted towards the middle of the solenoid, the current would change directions... but how does this relate to emf? and what would increasing the magnet strength even do... would it make a stronger magnetic field? I have no clue...
 
Physics news on Phys.org
Hi Sox281212, http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

What does Faraday's Law say about the situations described here?
 
Last edited by a moderator:
Thank you :)

Umm well EMF is proportional to the rate of change of the magnetic flux? :S
 
If I read this correctly, the situations they are comparing here both involve there being no relative movement. Is that your understanding?
 
Yep! Was just wondering, while waiting for your reply I was looking up some stuff; would doubling the magnetic strength also double the EMF? -just a thought haha..
 
A stronger magnet could be expected to induce a greater voltage as a generalization. But for the case in question, two times zero is still zero.
 
Oh okay... So.. There's No effect? :/
 
No relative movement means there is no induced emf.