# Homework Help: Magnetic Moment of loop

1. Apr 1, 2017

### superslow991

1. The problem statement, all variables and given/known data
A 15-turn rectangular loop of wire of width 10 cm and length 20 cm has a current of 2.5 A flowing through it. Two sides of the loop are oriented parallel to a uniform magnetic field of strength 0.037 T, and the other two sides are perpendicular to the magnetic field. (a) What is the magnitude of the magnetic moment of the loop? (b) What torque does the magnetic field exert on the loop?

2. Relevant equations

(a)- μ0 = NIA
(b)- torque = μ0 x B
3. The attempt at a solution
have the answer but would like to know the direction of A( area), the μ0, and also the direction of the field (B) and the torque.

I believe A's direction is perpendicular to the loop?
im unsure for the mu, Torque, and field

Last edited: Apr 2, 2017
2. Apr 2, 2017

### kuruman

Yes.
The magnetic moment is in the same direction as A.
The field direction is incompletely specified here as in the plane of the loop and perpendicular to two sides (which two?)
The torque is given by $\vec{\mu}\times \vec{B}$, but only its magnitude can be calculated because the direction of the field is unknown.

3. Apr 2, 2017

### superslow991

So is the field's direction perpendicular to the current and magnetic moment?

4. Apr 4, 2017