# Electromagnetic induction question

1. Jun 12, 2006

### fishmonger

I'm stuck on this homework question and it's due tomorrow.
Any help would be greatly appreciated...

Question:
A magnetic field of strength 2.3 T is directed into the plane of a square loop of wire with each side of length 0.4 m. The loop of wire is then crushed together in .48 seconds so that the loop no longer encloses any area. Find the total amount of charge flowing through the loop if the wire has a resistance of 0.2 .

2. Jun 12, 2006

### Hootenanny

Staff Emeritus
Hi there fishmonger and welcome to PF,

What are your thoughts thus far on this conundrum?

3. Jun 12, 2006

### fishmonger

Here are my thoughts thus far:

The change in the area within the loop (because of the crushing) should affect the magnetic flux, and the change in flux is what creates the emf...is as far a connection as I've been able to make.
I can't seem to figure out what equation to proceed with in order to actually calculate anything. Lenz's Law, or something completely different...?

4. Jun 12, 2006

### fishmonger

And thanks for the welcome! :) I wish I'd discovered this forum earlier in the year.

5. Jun 12, 2006

### Hootenanny

Staff Emeritus
You are quite correct. What you have just (almost) described is Faraday's law. Do you know what Faraday's law is?