# Wire Attracts Loop - Electromagnetic Unit

1. May 10, 2015

### Angie K.

1. The problem statement, all variables and given/known data

A rectangular loop of wire is placed next to a straight wire, as shown above. There is a current I in both the straight wire and the loop. The dimensions shown in the figure are a, b = 2.2a, and c = 8a. What is the magnitude of the force on the loop? Express your answer in terms of I, a, and μ0.

2. Relevant equations

B = (μ0 * I)/(2pi*d)

3. The attempt at a solution

Wouldn't I just use the equation from above and just use the value for b as the distance (d) ?

What is different in this problem that would require the equation to be different

2. May 11, 2015

where is the figure?

3. May 16, 2015

### Angie K.

Sorry, I forgot to put the figure up. Here it is!

So another attempt at this solution is:

F = I B L

where B = mu0 I / 2 pi a where a is the distance between the wires

so the final equation:

F = I * mu0 I / 2 pi a * 2.2a

where b = 2.2a is the length from the figure

4. May 17, 2015

### rude man

There are two forces on the loop: one in one direction, the other in the other. So you need 2 equations. Figure out the net force on the loop.

5. May 17, 2015