A Single Turn, Square Loop (torque)

1. Feb 14, 2010

DeltaIceman

1. The problem statement, all variables and given/known data
A 0.790 m length of wire is formed into a single-turn, square loop in which there is a current of 12.4 A. The loop is placed in a magnetic field of 0.146 T, as shown in the figure below.

http://img294.imageshack.us/img294/5043/cutj2167.gif [Broken]
2. Relevant equations

Net torque = NIABsin(theta)

3. The attempt at a solution
Okay so looking at the problem. I see that a wire the length of .790 is bent to for a single-turn square. So I take my length and divide it by 2. Which should be the length of each side of the square now.
Now the area of a square is A = l*w or one of your sides squared. So that would give me an A of .156 m^2.

Now as for N should it not just be 1. Since its a single turn square.

B = .146
I = 12.4
Also since im looking for the maximum torque it should be a sin(90) correct?

Well anyway when I use this formula I'm not getting the correct answer. So if someone could steer me in the right direction that would be great :).

Last edited by a moderator: May 4, 2017
2. Feb 15, 2010

ehild

How many sides does a square have?

ehild

3. Feb 15, 2010

DeltaIceman

A square has 4 sides. But since its a single loop square doesn't it only have 2 sides?

4. Feb 15, 2010

DeltaIceman

I mean not that the square in general has 2 sides. I know thats not possible. But I thought that when it said a single turn it meant that the length .709 was the first 2 sides of the square... |_ <- like that if it makes sense. And I just divided the length by 2 to get the length of one side. Anyway thats what I think of when it says single turn.

5. Feb 15, 2010

ehild

Well, it might have been better to say "single loop" in the problem. You need the area of the loop to get the torque. A single turn "L" shape has no area.

ehild

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