Turn on thread page Beta
 You are Here: Home >< Physics

# Magnetic fields & electromagnetic induction watch

1. Hi, im just wondering are there 2/theoretically infinite no. of magnetic fields, for say a current carrying wire, place in between 2 bar magnets?

For example, if a current carrying wire is place in a magnetic field, between 2 bar magnets, it will experience a magnet force (from flemings left hand rule).

However, am I right in saying there will be a magnetic field surrounding the current carrying wire anyway, due to it carrying a current? (So there will be a "double" magnetic field effectively?).

Also, same with generators. If there is relative motion a wire (not carrying current) in a magnetic field, between 2 bar magnets, then a current will be induced across it?
But then since it is now carrying a current, it will also prodce a magnetic field of its own? (So you almost get an endless loop of magnetic fields?)

Is my understanding here correct? And how do these 2 magnetic fields "interact"?

Thanks

Note: im doing aqa spec, physics a
2. (Original post by JohnnyDavidson)
Hi, im just wondering are there 2/theoretically infinite no. of magnetic fields, for say a current carrying wire, place in between 2 bar magnets?

For example, if a current carrying wire is place in a magnetic field, between 2 bar magnets, it will experience a magnet force (from flemings left hand rule).

However, am I right in saying there will be a magnetic field surrounding the current carrying wire anyway, due to it carrying a current? (So there will be a "double" magnetic field effectively?).

Also, same with generators. If there is relative motion a wire (not carrying current) in a magnetic field, between 2 bar magnets, then a current will be induced across it?
But then since it is now carrying a current, it will also prodce a magnetic field of its own? (So you almost get an endless loop of magnetic fields?)

Is my understanding here correct? And how do these 2 magnetic fields "interact"?

Thanks

Note: im doing aqa spec, physics a
Look up 'back emf' and Lenz's law.

It's essentially conservation of energy/momentum.

The e.m.f. set up in the conductor by moving the through a magnetic field, will generate a magnetic field (induced field) which will oppose any change in the motion/field.

The same is true for a changing current - an e.m.f. will be set up in the conductor in opposition to the changing current.

Reply
Submit reply
Turn on thread page Beta

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 14, 2016
Today on TSR

### My dream is to become a WAG

I wont settle for anything else!

### Games with LGBT+ characters/themes

Poll

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.